TWILIO INC 10-K

Item 8. Financial Statements and Supplementary Data INDEX TO CONSOLIDATED FINANCIAL STATEMENTS Page Reports of Independent Registered Public Accounting Firm ( PCAOB ID: 185 ) 75 Consolidated Balance Sheets 78 Consolidated Statements of Operations 79 Consolidated Statements of Comprehensive Loss 80 Consolidated Statements of Stockholders' Equity 81 Consolidated Statements of Cash Flows 83 Notes to Consolidated Financial Statements 84 74 Table of Contents Report of Independent Registered Public Accounting Firm To the Stockholders and Board of Directors Twilio Inc.: Opinions on the Consolidated Financial Statements and Internal Control Over Financial Reporting We have audited the accompanying consolidated balance sheets of Twilio Inc. and subsidiaries (the "Company") as of December 31, 2021 and 2020, the related consolidated statements of operations, comprehensive loss, stockholders’ equity and cash flows for each of the years in the three-year period ended December 31, 2021, and the related notes (collectively, the "consolidated financial statements"). We also have audited the Company’s internal control over financial reporting as of December 31, 2021, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2021 and 2020, and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, 2021, in conformity with U.S. generally accepted accounting principles. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2021, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. The Company acquired Zipwhip, Inc. during fiscal 2021, and management excluded from its assessment of the effectiveness of the Company’s internal control over financial reporting as of December 31, 2021, Zipwhip, Inc.’s internal control over financial reporting associated with total assets of $51.9 million and total revenues of $55.4 million included in the consolidated financial statements of the Company as of and for the year ended December 31, 2021. Our audit of internal control over financial reporting of the Company also excluded an evaluation of the internal control over financial reporting of Zipwhip, Inc. Basis for Opinions The Company’s management is responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Annual Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company’s consolidated financial statements and an opinion on the Company’s internal control over financial reporting based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects. Our audits of the consolidated financial statements included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions. 75 Table of Contents Definition and Limitations of Internal Control Over Financial Reporting A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements. Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. Critical Audit Matters The critical audit matters communicated below are matters arising from the current period audit of the consolidated financial statements that were communicated or required to be communicated to the audit committee and that: (1) relate to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matters below, providing separate opinions on the critical audit matters or on the accounts or disclosures to which they relate. Evaluation of the sufficiency of audit evidence over revenue recognition As discussed in Note 2(e) to the consolidated financial statements, the Company's revenue is derived from usage and non-usage based fees earned from customers accessing the Company's enterprise cloud computing services. As of December 31, 2021, the Company recorded $2.8 billion in revenues, a portion of which related to Programmable Messaging and Programmable Voice APIs. The Company’s revenue recognition process is highly automated and revenue is recorded within the Company’s general ledger through reliance on customized and proprietary information technology (IT) systems. We identified the evaluation of the sufficiency of audit evidence over revenue recognition related to the Company’s Programmable Messaging and Programmable Voice APIs as a critical audit matter. This matter required especially subjective auditor judgment because of the large number of information technology (IT) applications involved in the revenue recognition process. Auditor judgment was required in determining the nature and extent of audit evidence obtained over these information systems that process revenue transactions. Involvement of IT professionals with specialized skills and knowledge was required to assist with the performance and evaluation of certain procedures and determination of IT applications subject to testing. The following are the primary procedures we performed to address this critical audit matter. We applied auditor judgment to determine the nature and extent of procedures to be performed over revenue recognition. We evaluated the design and tested the operating effectiveness of certain internal controls related to the Company’s Programmable Messaging and Programmable Voice revenue recognition process. We involved IT professionals with specialized skills and knowledge, who assisted in testing controls related to the Company’s general information technology and application controls related to the systems utilized within the Company’s Programmable Messaging and Programmable Voice revenue recognition process. For a sample of customer agreements, we tested the Company’s identification and treatment of significant contract terms, including comparing the pricing reflected in the Company’s revenue IT system to the contractually agreed upon pricing with the customer. For a sample of revenue transactions, we compared the amounts recognized for consistency with underlying documentation, including contracts with customers. We assessed the recorded revenue by comparing revenue to underlying cash receipts. We evaluated credits issued after year end to assess the revenue recorded within the period. In addition, we evaluated the overall sufficiency of audit evidence obtained by assessing the results of procedures performed, including appropriateness of the nature and extent of such evidence. 76 Table of Contents Valuation of the acquisition date intangible assets related to a business combination As discussed in Note 7 to the consolidated financial statements, on July 14, 2021, the Company acquired Zipwhip, Inc. (Zipwhip) by issuing shares of its Class A common stock worth approximately $419.2 million and paying approximately $418.1 million of cash. As part of the acquisition, the Company acquired $244.5 million of intangible assets, including customer relationships. We identified the assessment of the valuation of the acquisition date customer relationship intangible asset acquired as a critical audit matter. There was a high degree of subjective auditor judgment in assessing the discount rate and forecasted revenue growth rates used to derive the fair value of the customer relationship acquired intangible asset. In addition, this fair value was challenging to test due to the sensitivity of the fair value determination to changes in these assumptions. The following are the primary procedures we performed to address the critical audit matter. We evaluated the design and tested the operating effectiveness of certain internal controls over the Company’s process to value acquired intangible assets, including the Company’s controls over the discount rate and forecasted revenue growth rate. We compared prior period forecasted revenue to prior period actual revenue to evaluate the Company’s ability to forecast. We evaluated the Company’s forecasted revenue growth rates used to value the customer relationship intangible asset by (1) comparing the growth forecast assumptions to historical growth rates of peer companies, and (2) comparing forecasted growth rates to historical growth rates. We involved a valuation professional with specialized skills and knowledge, who assisted in testing by: • evaluating the discount rate used by the Company to value the customer relationship intangible asset by assessing the relevant inputs used by the Company in their calculation of their discount rate • recalculating the estimate of the fair value of the customer relationship intangible asset acquired using the Company’s cash flow forecast and discount rate independently corroborated by our valuation specialists and comparing the result to the Company’s fair value estimate. /s/ KPMG LLP We have served as the Company’s auditor since 2013. Santa Clara, California February 22, 2022 77 Table of Contents TWILIO INC. Consolidated Balance Sheets As of December 31, 2021 2020 (In thousands, except share and per share amounts) ASSETS Current assets: Cash and cash equivalents $ 1,479,452 $ 933,885 Short-term marketable securities 3,878,430 2,105,906 Accounts receivable, net 388,215 251,167 Prepaid expenses and other current assets 186,131 81,377 Total current assets 5,932,228 3,372,335 Property and equipment, net 255,316 183,239 Operating right-of-use assets 234,584 258,610 Intangible assets, net 1,050,012 966,573 Goodwill 5,263,166 4,595,394 Other long-term assets 263,292 111,282 Total assets $ 12,998,598 $ 9,487,433 LIABILITIES AND STOCKHOLDERS’ EQUITY Current liabilities: Accounts payable $ 93,333 $ 60,042 Accrued expenses and other current liabilities 417,503 252,895 Deferred revenue and customer deposits 140,389 87,031 Operating lease liability, current 52,325 48,338 Total current liabilities 703,550 448,306 Operating lease liability, noncurrent 211,253 229,905 Finance lease liability, noncurrent 25,132 17,856 Long-term debt 985,907 302,068 Other long-term liabilities 41,290 36,633 Total liabilities 1,967,132 1,034,768 Commitments and contingencies (Note 13) Stockholders’ equity: Preferred stock, $ 0.001 par value, 100,000,000 shares authorized, none issued — — Class A and Class B common stock, $ 0.001 par value per share Authorized shares 1,100,000,000 as of December 31, 2021 and 2020; Issued and outstanding shares 180,468,099 and 164,047,524 as of December 31, 2021 and 2020 180 164 Additional paid-in capital 13,169,118 9,613,246 Accumulated other comprehensive (loss) income ( 18,141 ) 9,046 Accumulated deficit ( 2,119,691 ) ( 1,169,791 ) Total stockholders’ equity 11,031,466 8,452,665 Total liabilities and stockholders’ equity $ 12,998,598 $ 9,487,433 See accompanying notes to consolidated financial statements. 78 TWILIO INC. Consolidated Statements of Operations Year Ended December 31, 2021 2020 2019 (In thousands, except share and per share amounts) Revenue $ 2,841,839 $ 1,761,776 $ 1,134,468 Cost of revenue 1,451,126 846,115 525,551 Gross profit 1,390,713 915,661 608,917 Operating expenses: Research and development 789,219 530,548 391,355 Sales and marketing 1,044,618 567,407 369,079 General and administrative 472,460 310,607 218,268 Total operating expenses 2,306,297 1,408,562 978,702 Loss from operations ( 915,584 ) ( 492,901 ) ( 369,785 ) Other (expenses) income, net ( 45,345 ) ( 11,525 ) 7,569 Loss before benefit for income taxes ( 960,929 ) ( 504,426 ) ( 362,216 ) Benefit for income taxes 11,029 13,447 55,153 Net loss attributable to common stockholders $ ( 949,900 ) $ ( 490,979 ) $ ( 307,063 ) Net loss per share attributable to common stockholders, basic and diluted $ ( 5.45 ) $ ( 3.35 ) $ ( 2.36 ) Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 174,180,465 146,708,663 130,083,046 See accompanying notes to consolidated financial statements. 79 TWILIO INC. Consolidated Statements of Comprehensive Loss Year Ended December 31, 2021 2020 2019 (In thousands) Net loss $ ( 949,900 ) $ ( 490,979 ) $ ( 307,063 ) Other comprehensive (loss) income: Unrealized (loss) gain on marketable securities ( 27,215 ) 3,674 3,804 Foreign currency translation ( 266 ) 286 — Net change in market value of effective foreign currency forward exchange contracts 294 — — Total other comprehensive (loss) income ( 27,187 ) 3,960 3,804 Comprehensive loss attributable to common stockholders $ ( 977,087 ) $ ( 487,019 ) $ ( 303,259 ) See accompanying notes to consolidated financial statements. 80 TWILIO, INC. Consolidated Statements of Stockholder's Equity Common Stock Class A Common Stock Class B Additional Paid-In Capital Accumulated Other Comprehensive Income Accumulated Deficit Total Stockholders' Equity Shares Amount Shares Amount (In thousands, except share amounts) Balance as of December 31, 2018 80,769,763 $ 80 19,310,465 $ 20 $ 808,527 $ 1,282 $ ( 371,674 ) $ 438,235 Net loss — — — — — — ( 307,063 ) ( 307,063 ) Exercises of stock options 1,466,813 1 2,154,053 2 37,760 — — 37,763 Recapitalization of a subsidiary — — — — 75 — ( 75 ) — Vesting of restricted stock units 2,775,788 2 117,331 1 — — — 3 Value of equity awards withheld for tax liability ( 23,543 ) — ( 22,095 ) — ( 5,412 ) — — ( 5,412 ) Conversion of shares of Class B common stock into shares of Class A common stock 10,029,127 9 ( 10,029,127 ) ( 9 ) — — — — Shares of Class A common stock issued under ESPP 244,628 — — — 19,738 — — 19,738 Shares of Class A common stock issued in connection with a follow-on public offering, net of underwriters' discounts and issuance costs 8,064,515 8 — — 979,039 979,047 Shares of Class A common stock issued in acquisition 23,555,081 24 — — 2,658,874 — — 2,658,898 Value of equity awards assumed in acquisition — — — — 182,554 — — 182,554 Unrealized gain on marketable securities — — — — — 3,804 — 3,804 Stock-based compensation — — — — 271,844 — — 271,844 Balance as of December 31, 2019 126,882,172 $ 124 11,530,627 $ 14 $ 4,952,999 $ 5,086 $ ( 678,812 ) $ 4,279,411 Net loss — — — — — — ( 490,979 ) ( 490,979 ) Exercises of stock options 2,263,629 2 1,232,099 1 72,514 — — 72,517 Vesting of restricted stock units 3,525,401 4 29,007 — — — — 4 Value of equity awards withheld for tax liability ( 34,893 ) — ( 4,692 ) — ( 8,778 ) — — ( 8,778 ) Conversion of shares of Class B common stock into shares of Class A common stock 2,235,739 2 ( 2,235,739 ) ( 2 ) — — — — Equity component from partial settlement of convertible senior notes due 2023 2,902,434 3 — — 190,757 — — 190,760 Shares of Class A common stock issued under ESPP 291,800 1 — — 32,242 — — 32,243 Shares of Class A common stock donated to charity 88,408 — — — 18,993 — — 18,993 Issuance of shares of Class A common stock in connection with a follow-on public offering, net of underwriters' discounts and issuance costs 5,819,838 6 — — 1,408,163 — — 1,408,169 Shares of Class A common stock issued in acquisition 9,263,140 9 — — 2,532,347 — — 2,532,356 Value of equity awards assumed in acquisition — — — — 38,972 — — 38,972 Shares of Class A common stock issued in acquisition subject to future vesting 258,554 — — — — — — — Unrealized gain on marketable securities — — — — — 3,674 — 3,674 Foreign currency translation — — — — — 286 — 286 Stock-based compensation — — — — 375,037 — — 375,037 Balance as of December 31, 2020 153,496,222 $ 151 10,551,302 $ 13 $ 9,613,246 $ 9,046 $ ( 1,169,791 ) $ 8,452,665 81 TWILIO, INC. Consolidated Statements of Stockholder's Equity Common Stock Class A Common Stock Class B Additional Paid-In Capital Accumulated Other Comprehensive Income Accumulated Deficit Total Stockholders' Equity Shares Amount Shares Amount (In thousands, except share amounts) Balance as of December 31, 2020 153,496,222 $ 151 10,551,302 $ 13 $ 9,613,246 $ 9,046 $ ( 1,169,791 ) $ 8,452,665 Net loss — — — — — — ( 949,900 ) ( 949,900 ) Exercises of stock options 1,779,320 2 509,499 — 87,693 — — 87,695 Vesting of restricted stock units 3,515,913 4 — — ( 4 ) — — — Value of equity awards withheld for tax liability ( 32,002 ) — — — ( 10,388 ) — — ( 10,388 ) Conversion of shares of Class B common stock into shares of Class A common stock 1,218,696 1 ( 1,218,696 ) ( 1 ) — — — — Equity component from partial settlement and redemption of convertible senior notes due 2023 4,846,965 5 — — 335,637 — — 335,642 Settlement of capped call, net of related costs — — — — 225,233 — — 225,233 Shares of Class A common stock issued under ESPP 198,926 — — — 48,465 — — 48,465 Shares of Class A common stock donated to charity 88,408 — — — 31,169 — — 31,169 Issuance of shares of Class A common stock in connection with a follow-on public offering, net of underwriters' discounts and issuance costs 4,312,500 4 — — 1,765,709 — — 1,765,713 Shares of Class A common stock issued in acquisition 1,116,816 1 — — 419,169 — — 419,170 Value of equity awards assumed in acquisition — — — — 1,511 — — 1,511 Shares of Class A common stock subject to future vesting 84,230 — — — — — — — Unrealized loss on marketable securities — — — — — ( 27,215 ) — ( 27,215 ) Foreign currency translation — — — — — ( 266 ) — ( 266 ) Net change in market value of effective foreign currency forward exchange contracts — — — — — 294 — 294 Stock-based compensation — — — — 651,678 — — 651,678 Balance as of December 31, 2021 170,625,994 $ 168 9,842,105 $ 12 $ 13,169,118 $ ( 18,141 ) $ ( 2,119,691 ) $ 11,031,466 See accompanying notes to consolidated financial statements. 82 TWILIO INC . Consolidated Statements of Cash Flows Year Ended December 31, 2021 2020 2019 CASH FLOWS FROM OPERATING ACTIVITIES: (In thousands) Net loss $ ( 949,900 ) $ ( 490,979 ) $ ( 307,063 ) Adjustments to reconcile net loss to net cash (used in) provided by operating activities: Depreciation and amortization 258,378 149,660 110,430 Non-cash reduction to the right-of-use asset 48,786 38,395 23,193 Net amortization of investment premium and discount 36,158 6,789 ( 4,501 ) Impairment of operating right-of-use assets 8,854 — — Amortization of debt discount and issuance costs 5,827 23,759 23,696 Stock-based compensation 632,285 360,936 264,318 Amortization of deferred commissions 31,541 13,322 4,511 Tax benefit related to release of valuation allowance ( 17,236 ) ( 16,459 ) ( 55,745 ) Value of shares of Class A common stock donated to charity 31,169 18,993 — Loss on extinguishment of debt 28,965 12,863 — Other adjustments 12,094 12,762 3,165 Changes in operating assets and liabilities: Accounts receivable ( 117,943 ) ( 81,303 ) ( 51,357 ) Prepaid expenses and other current assets ( 78,012 ) ( 11,636 ) ( 20,316 ) Other long-term assets ( 121,225 ) ( 81,908 ) ( 18,021 ) Accounts payable 10,191 10,060 17,255 Accrued expenses and other current liabilities 127,554 88,340 46,154 Deferred revenue and customer deposits 45,634 13,824 2,968 Operating lease liabilities ( 49,046 ) ( 33,938 ) ( 21,138 ) Other long-term liabilities ( 2,266 ) ( 826 ) ( 3,501 ) Net cash (used in) provided by operating activities ( 58,192 ) 32,654 14,048 CASH FLOWS FROM INVESTING ACTIVITIES: Acquisitions, net of cash acquired and other related payments ( 491,522 ) ( 333,591 ) 122,749 Purchases of marketable securities and other investments ( 3,523,232 ) ( 1,636,590 ) ( 2,038,422 ) Proceeds from sales and maturities of marketable securities 1,614,779 1,183,459 697,171 Capitalized software development costs ( 43,973 ) ( 33,328 ) ( 21,922 ) Purchases of long-lived and intangible assets ( 46,048 ) ( 25,805 ) ( 45,368 ) Net cash used in investing activities ( 2,489,996 ) ( 845,855 ) ( 1,285,792 ) CASH FLOWS FROM FINANCING ACTIVITIES: Proceeds from public offerings, net of underwriters' discount and issuance costs 1,765,713 1,408,113 979,123 Proceeds from issuance of senior notes due 2029 and 2031 987,500 — — Payment of debt issuance costs ( 2,777 ) — — Principal payments on debt and finance leases ( 8,295 ) ( 10,784 ) ( 11,046 ) Proceeds from exercises of stock options and shares of Class A common stock issued under ESPP 136,160 104,760 57,480 Proceeds from settlements of capped call, net of settlement costs 228,412 — — Value of equity awards withheld for tax liabilities ( 10,388 ) ( 8,778 ) ( 5,412 ) Net cash provided by financing activities 3,096,325 1,493,311 1,020,145 Effect of exchange rate changes on cash, cash equivalents and restricted cash ( 191 ) 40 — NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH 547,946 680,150 ( 251,599 ) CASH, CASH EQUIVALENTS AND RESTRICTED CASH—Beginning of year 933,885 253,735 505,334 CASH, CASH EQUIVALENTS AND RESTRICTED CASH —End of year $ 1,481,831 $ 933,885 $ 253,735 Cash paid for income taxes, net $ 6,147 $ 3,092 $ 1,368 Cash paid for interest $ 20,637 $ 2,139 $ 2,290 NON-CASH INVESTING AND FINANCING ACTIVITIES: Purchases of property and equipment through finance leases $ 22,157 $ 20,108 $ 5,848 Value of common stock issued and equity awards assumed in acquisition $ 420,681 $ 2,571,328 $ 2,841,452 Value of common stock issued to settle convertible senior notes due 2023 $ 1,704,969 $ 892,640 $ — RECONCILIATION OF CASH, CASH EQUIVALENTS AND RESTRICTED CASH TO THE CONSOLIDATED BALANCE SHEETS Cash and cash equivalents $ 1,479,452 $ 933,885 $ 253,735 Restricted cash in other current assets 1,536 — — Restricted cash in other long-term assets 843 — — Total cash, cash equivalents and restricted cash $ 1,481,831 $ 933,885 $ 253,735 See accompanying notes to consolidated financial statements. 83 Table of Contents TWILIO INC. Notes to Consolidated Financial Statements 1. Organization and Description of Business Twilio Inc. (the “Company”) was incorporated in the state of Delaware on March 13, 2008. The Company is the leading cloud communications platform and enables developers to build, scale and operate real-time customer engagement within their software applications via simple-to-use Application Programming Interfaces (“API”). The power, flexibility, and reliability offered by the Company’s software building blocks empower entities of virtually every shape and size to build world-class engagement into their customer experience. The Company’s headquarters are located in San Francisco, California, and the Company has subsidiaries across North America, South America, Europe, Asia and Australia. 2. Summary of Significant Accounting Policies (a) Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). (b) Principles of Consolidation The consolidated financial statements include the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated. (c) Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. These estimates are used for, but not limited to, revenue allowances and sales credit reserves; recoverability of long-lived and intangible assets; capitalization and useful life of the Company’s capitalized internal-use software development costs; fair value of acquired intangible assets and goodwill; accruals and contingencies. Estimates are based on historical experience and on various assumptions that the Company believes are reasonable under current circumstances. However, future events are subject to change and best estimates and judgments may require further adjustments, therefore, actual results could differ materially from those estimates. Management periodically evaluates such estimates and they are adjusted prospectively based upon such periodic evaluation. (d) Concentration of Credit Risk Financial instruments that potentially expose the Company to a concentration of credit risk consist primarily of cash, cash equivalents, restricted cash, marketable securities and accounts receivable. The Company maintains cash, restricted cash, cash equivalents and marketable securities with financial institutions that management believes are financially sound and have minimal credit risk exposure although the balances will exceed insured limits. The Company sells its services to a wide variety of customers. If the financial condition or results of operations of any significant customer deteriorates substantially, operating results could be adversely affected. To reduce credit risk, management performs credit evaluations of the financial condition of significant customers. The Company does not require collateral from its credit customers and maintains reserves for estimated credit losses on customer accounts when considered necessary. Actual credit losses may differ from the Company’s estimates. During the years ended December 31, 2021, 2020 and 2019, no customer organization accounted for more than 10% of the Company’s total revenue. As of December 31, 2021 and 2020, no customer organization represented more than 10% of the Company’s gross accounts receivable. 84 Table of Contents (e) Revenue Recognition Revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. The Company enters into contracts that can include various combinations of products and services, which are generally capable of being distinct and accounted for as separate performance obligations. Revenue is recognized net of allowances for credits and any taxes collected from customers, which are subsequently remitted to governmental authorities. The Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer; • Identification of the performance obligations in the contract; • Determination of the transaction price; • Allocation of the transaction price to the performance obligations in the contract; and, • Recognition of revenue when, or as, the Company satisfies a performance obligation. Nature of Products and Services The Company's revenue is primarily derived from usage-based fees earned from customers accessing the Company's enterprise cloud computing services. Platform access is considered a monthly series comprising of one performance obligation and usage-based fees are recognized as revenue in the period in which the usage occurs. In the years ended December 31, 2021, 2020 and 2019, the revenue from usage-based fees represented 72 %, 76 % and 75 % of total revenue, respectively. Subscription-based fees are derived from certain non-usage-based contracts, such as those for the sales of short codes, customer support and fees charged to access the cloud-based platform of Segment io, Inc. (“Segment”), which the Company acquired in 2020 as further described in Note 7. Non-usage-based contracts revenue is recognized on a ratable basis over the contractual term which is generally between one to three years . In the years ended December 31, 2021, 2020 and 2019, the revenue from non-usage-based fees represented 28 %, 24 %, and 25 % of total revenue, respectively. No significant judgments are required in determining whether products and services are considered distinct performance obligations and should be accounted for separately versus together, or to determine the stand-alone selling price (“SSP”). The Company's arrangements do not contain general rights of return. However, credits may be issued on a case-by-case basis. The contracts do not provide customers with the right to take possession of the software supporting the applications. Amounts that have been invoiced are recorded in accounts receivable and in revenue or deferred revenue depending on whether the revenue recognition criteria have been met. Remaining Performance Obligations Revenue allocated to remaining performance obligations represents unearned revenue and amounts that were and will be invoiced and recognized as revenue in future periods for non-cancelable multi-year subscription arrangements. The Company applies the optional exemption of not disclosing the transaction price allocated to the remaining performance obligations for its usage-based contracts and contracts with original duration of one year or less. Revenue allocated to remaining performance obligations for contracts with durations of more than one year was $ 154.2 million as of December 31, 2021, of which 62 % is expected to be recognized over the next 12 months and 92 % is expected to be recognized over the next 24 months. (f) Deferred Revenue and Customer Deposits Deferred revenue is recorded when a non-cancellable contractual right to bill exists or when cash payments are received in advance of future usage on non-cancelable contracts. Customer refundable prepayments are recorded as customer deposits. As of December 31, 2021 and 2020, the Company recorded $ 141.5 million and $ 87.2 million as its deferred revenue and customer deposits, respectively, that are included in deferred revenue and customer deposits and other long-term liabilities in the accompanying consolidated balance sheets. During the years ended December 31, 2021, 2020 and 2019, the Company recognized $ 70.1 million, $ 19.5 million and $ 18.7 million of revenue, respectively, that was included in the deferred revenue and customer deposits balance as of the end of the previous year. 85 Table of Contents (g) Deferred Sales Commissions The Company records an asset for the incremental costs of obtaining a contract with a customer, for example, sales commissions that are earned upon execution of contracts. The Company uses the portfolio of data method to determine the estimated period of benefit of capitalized commissions which is generally determined to be up to five years . Amortization expense related to these capitalized costs related to initial contracts, upsells and renewals, is recognized on a straight line basis over the estimated period of benefit of the capitalized commissions. The Company applies the optional exemption of expensing these costs as incurred with amortization periods of one year or less. Total net capitalized costs as of December 31, 2021 and 2020, were $ 193.4 million and $ 85.6 million, respectively, and are included in prepaid expenses and other current assets and other long‑term assets in the accompanying consolidated balance sheets. Amortization of these assets was $ 31.5 million, $ 13.3 million and $ 4.5 million in the years ended December 31, 2021, 2020 and 2019, respectively, and is included in sales and marketing expense in the accompanying consolidated statements of operations. (h) Cost of Revenue Cost of revenue consists primarily of costs of communications services purchased from network service providers. Cost of revenue also includes fees to support the Company's cloud infrastructure, direct costs of personnel, such as salaries and stock-based compensation for the customer care and support services employees, and non-personnel costs, such as amortization of capitalized internal-use software development costs and amortization of acquired intangibles. (i) Research and Development Expense Research and development expenses consist primarily of personnel costs, cloud infrastructure fees for staging and development, outsourced engineering services, amortization of capitalized internal-use software development costs and an allocation of general overhead expenses. The Company capitalizes the portion of its software development costs that meets the criteria for capitalization. (j) Internal-Use Software Development Costs Certain costs of platform and other software applications developed for internal use are capitalized. The Company capitalizes qualifying internal-use software development costs that are incurred during the application development stage. Capitalization of costs begins when two criteria are met: (i) the preliminary project stage is completed and (ii) it is probable that the software will be completed and used for its intended function. Capitalization ceases when the software is substantially complete and ready for its intended use, including the completion of all significant testing. The Company also capitalizes costs related to specific upgrades and enhancements when it is probable the expenditures will result in additional functionality. Costs incurred for maintenance, minor upgrades and enhancements are expensed. Costs related to preliminary project activities and post-implementation operating activities are also expensed as incurred. Capitalized costs of platform and other software applications are included in property and equipment. These costs are amortized over the estimated useful life of the software on a straight-line basis over three years . Management evaluates the useful life of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. The amortization of costs related to the platform applications is included in cost of revenue, while the amortization of costs related to other software applications developed for internal use is included in operating expenses. (k) Advertising Costs Advertising costs are expensed as incurred and were $ 78.8 million, $ 47.2 million and $ 27.0 million in the years ended December 31, 2021, 2020 and 2019, respectively. Advertising costs are included in sales and marketing expenses in the accompanying consolidated statements of operations. (l) Stock-Based Compensation All stock-based compensation to employees, including the purchase rights issued under the Company's 2016 Employee Stock Purchase Plan (the “ESPP”), is measured on the grant date based on the fair value of the awards on the date of grant. These costs are recognized as an expense following straight-line attribution method over the requisite service period. The Company uses the Black-Scholes option pricing model to measure the fair value of its stock options and the purchase rights 86 Table of Contents issued under the ESPP. The fair value of the restricted stock units is determined using the fair value of the Company's Class A common stock on the date of grant and recognized as an expense following straight-line attribution method over the requisite service period. Forfeitures are recorded in the period in which they occur. Compensation expense for stock options granted to nonemployees is calculated using the Black-Scholes option pricing model and is recognized in expense over the service period. The Black-Scholes option pricing model requires the use of complex assumptions, which determine the fair value of stock options and the purchase rights issued under ESPP. These assumptions include: • Fair value of the common stock. The Company uses the market closing price of its Class A common stock, as reported on the New York Stock Exchange, for the fair value. • Expected term. The expected term represents the period that the stock option or the purchase right is expected to be outstanding. The Company uses the simplified calculation of expected term, which reflects the weighted-average time-to-vest and the contractual life of the stock option or the purchase right; • Expected volatility. Prior to July 1, 2021, the expected volatility was derived from an average of the historical volatilities of the Class A common stock of the Company and several other entities with characteristics similar to those of the Company, such as the size and operational and economic similarities to the Company's principal business operations. Beginning with the third quarter 2021, the expected volatility was derived from the average of the historical volatilities of the Class A common stock of the Company. • Risk -free interest rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero coupon U.S. Treasury notes with maturities approximately equal to the expected term of the stock-based awards; and • Expected dividend. The expected dividend is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock. If any of the assumptions used in the Black-Scholes model changes, stock-based compensation for future options may differ materially compared to that associated with previous grants. Income Taxes The Company accounts for income taxes in accordance with authoritative guidance which requires the use of the asset and liability approach. Deferred tax assets and liabilities are recognized for future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as net operating loss and tax credit carry-forwards. Deferred tax amounts are determined by using the enacted tax rates expected to be in effect when the temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance reduces the deferred tax assets to the amount that is more likely than not to be realized. The Company recognizes the effect of uncertain income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company records interest and penalties related to uncertain tax positions in the provision for income taxes in the consolidated statements of operations. (m) Foreign Currency Translation The functional currency of the Company's foreign subsidiaries is generally the U.S. dollar. Accordingly, the subsidiaries remeasure monetary assets and liabilities at period-end exchange rates, while non-monetary items are remeasured at historical rates. Revenue and expense accounts are remeasured at the average exchange rate in effect during the year. Remeasurement adjustments are recognized in the consolidated statements of operations as other income or expense in the year of occurrence. Foreign currency transaction gains and losses were insignificant for all periods presented. 87 Table of Contents For those entities where the functional currency is a foreign currency, adjustments resulting from translating the financial statements into U.S. dollars are recorded as a component of accumulated other comprehensive (loss) income in stockholders' equity. Monetary assets and liabilities denominated in a foreign currency are translated into U.S. dollars at the exchange rate on the balance sheet date. Revenue and expenses are translated at the weighted average exchange rates during the period. Equity transactions are translated using historical exchange rates. Foreign currency transaction gains and losses are included in other (expenses) income, net in the consolidated statements of operations. (n) Comprehensive Loss Comprehensive loss refers to net loss and other revenue, expenses, gains and losses that, under generally accepted accounting principles, are recorded as an element of stockholders' equity but are excluded from the calculation of net loss. (o) Net Loss Per Share Attributable to Common Stockholders The Company calculates its basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for companies with participating securities. The Company has 100,000,000 shares of preferred stock that was authorized but never issued or outstanding. Class A and Class B common stock are the only outstanding equity of the Company. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 10 votes per share. Shares of Class B common stock may be converted into Class A common stock at any time at the option of the stockholder on a one -for-one basis, and are automatically converted into Class A common stock upon sale or transfer, subject to certain limited exceptions. Shares of Class A common stock are not convertible. The Company also has dilutive securities, such as potential or restricted common shares or common stock equivalents, that were excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive. These securities are presented in Note 16 to these consolidated financial statements. (p) Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of cash deposited into money market funds and commercial paper. All credit and debit card transactions that process as of the last day of each month and settle within the first few days of the subsequent month are also classified as cash and cash equivalents as of the end of the month in which they were processed. (q) Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded net of the allowance for doubtful accounts. The allowance for doubtful accounts is estimated based on the Company's assessment of its ability to collect on customer accounts receivable. The Company regularly reviews the allowance by considering certain factors such as historical experience, credit quality, age of accounts receivable balances and other known conditions that may affect a customer's ability to pay. In cases where the Company is aware of circumstances that may impair a specific customer's ability to meet their financial obligations, a specific allowance is recorded against amounts due from the customer which reduces the net recognized receivable to the amount the Company reasonably believe will be collected. The Company writes-off accounts receivable against the allowance when a determination is made that the balance is uncollectible and collection of the receivable is no longer being actively pursued. As of December 31, 2021 and 2020, the allowance for doubtful accounts was not significant to the accompanying consolidated balance sheets. (r) Costs Related to Public Offerings Costs related to public offerings, which consist of direct incremental legal, printing and accounting fees are deferred until the offering is completed. Upon completion of the offering, these costs are offset against the offering proceeds within the consolidated statements of stockholders' equity. (s) Property and Equipment Property and equipment, both owned and under finance leases, is stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful life of the related asset. Maintenance and repairs are charged to expenses as incurred. 88 Table of Contents The useful lives of property and equipment are as follows: Capitalized internal-use software development costs 3 years Data center equipment 2 - 4 years Office equipment 3 years Furniture and fixtures 5 years Software 3 years Assets under financing lease 5 years or remaining lease term Leasehold improvements 5 years or remaining lease term (t) Leases The Company determines if an arrangement is or contains a lease at contract inception. The Company presents the operating leases in long-term assets and current and long-term liabilities. Finance lease assets are included in property and equipment, net, and finance lease liabilities are presented in current and long-term liabilities in the accompanying consolidated balance sheets. Right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and lease liabilities are measured and recognized at the lease commencement date based on the present value of the remaining lease payments over the lease term. As the Company’s leases do not generally provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The Company’s lease agreements may have lease and non-lease components, which the Company accounts for as a single lease component. When estimating the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain such options will be exercised. Operating lease costs are recognized in operating expenses in the accompanying consolidated statements of operations on a straight-line basis over the lease term and variable payments are recognized in the period they are incurred. The Company’s lease agreements do not contain any residual value guarantees. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Within the consolidated statements of cash flows, the Company presents the lease payments made on the operating leases as cash flows from operations and principal payments made on the finance leases as part of financing activities. (u) Intangible Assets Intangible assets recorded by the Company are costs directly associated with securing legal registration of patents and trademarks, acquiring domain names and the fair value of identifiable intangible assets acquired in business combinations. Intangible assets with determinable economic lives are carried at cost, less accumulated amortization. Amortization is computed over the estimated useful life of each asset on a straight-line basis. The Company determines the useful lives of identifiable intangible assets after considering the specific facts and circumstances related to each intangible asset. Factors the Company considers when determining useful lives include the contractual term of any agreement related to the asset, the historical performance of the asset, the Company's long-term strategy for using the asset, any laws or other local regulations which could impact the useful life of the asset and other economic factors, including competition and specific market conditions. Intangible assets without determinable economic lives are carried at cost, not amortized and reviewed for impairment at least annually. 89 Table of Contents The useful lives of the intangible assets are as follows: Developed technology 3 - 7 years Customer relationships 2 - 10 years Supplier relationships 2 - 5 years Trade names 5 years Order backlog 1 year Patents 20 years Telecommunication licenses Indefinite Trademarks Indefinite Domain names Indefinite (v) Goodwill Goodwill represents the excess of the aggregate purchase price over the fair value of net identifiable assets acquired in a business combination. Goodwill is not amortized and is tested for impairment at least annually or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The Company has determined that it operates as one reporting unit and has selected November 30 as the date to perform its annual impairment test. In the valuation of goodwill, management must make assumptions regarding estimated future cash flows to be derived from the Company's business. If these estimates or their related assumptions change in the future, the Company may be required to record impairment for these assets. The Company has the option to first perform a qualitative assessment to determine if it is more likely than not that the fair value of a reporting unit is less than its carrying amount. However, the Company may elect to bypass the qualitative assessment and proceed directly to the quantitative impairment tests. The impairment test involves comparing the fair value of the reporting unit to its carrying value, including goodwill. A goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value. The impairment is limited to the carrying amount of goodwill. No goodwill impairment charges have been recorded for any period presented. (w) Derivatives and Hedging The Company is exposed to a wide variety of risks arising from its business operations and overall economic conditions. These risks include exposure to fluctuations in various foreign currencies against its functional currency and can impact the value of cash receipts and payments. The Company minimizes its exposure to these risks through management of its core business activities, specifically, the amounts, sources and duration of its assets and liabilities, and the use of derivative financial instruments. During 2021, the Company started using foreign currency derivative forward contracts and in the future may also use foreign currency option contacts. Foreign currency derivative forward contracts involve fixing the exchange rate for delivery of a specified amount of foreign currency on a specified date. These agreements are typically cash settled in U.S. dollars for their fair value at or close to their settlement date. Foreign currency option contracts will require the Company to pay a premium for the right to sell a specified amount of foreign currency prior to the maturity date of the option. The Company does not enter into derivative financial instruments trading for speculative purposes. Derivative instruments are carried at fair value and recorded as either an asset or a liability until they mature. Gains and losses resulting from changes in fair value of these instruments are accounted for depending on the use of the derivative and whether it is designated and qualifies for hedge accounting. For derivative instruments designated as cash flow hedges, gains or losses are initially recorded in other comprehensive income (“OCI”) in the balance sheet, then reclassified into the statement of operations in the period in which the derivative instruments mature. These realized gains and losses are recorded within the same financial statement line item as the hedged transaction. 90 Table of Contents The Company’s foreign currency derivative contracts are classified within Level 2 of the fair value hierarchy because the valuation inputs are based on quoted prices and market observable data of similar instruments in active markets, such as currency spot and forward rates. (x) Impairment of Long-Lived Assets The Company evaluates its long-lived assets, including property, equipment and intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets held and used is measured by a comparison of the carrying amount of an asset or an asset group to estimated undiscounted future net cash flows expected to be generated by the asset or asset group. If such evaluation indicates that the carrying amount of the asset or the asset group is not recoverable, any impairment loss would be equal to the amount the carrying value exceeds the fair value. There were no impairments during the years ended December 31, 2021, 2020 and 2019. (y) Business Combinations The Company recognizes identifiable assets acquired and liabilities assumed at their acquisition date fair values. Goodwill is measured as the excess of the consideration transferred over the fair value of assets acquired and liabilities assumed on the acquisition date. While the Company uses its best estimates and assumptions as part of the purchase price allocation process to accurately value assets acquired and liabilities assumed, these estimates are inherently uncertain and subject to refinement. The authoritative guidance allows a measurement period of up to one year from the date of acquisition to make adjustments to the preliminary allocation of the purchase price. As a result, during the measurement period the Company may record adjustments to the fair values of assets acquired and liabilities assumed, with the corresponding offset to goodwill to the extent that it identifies adjustments to the preliminary purchase price allocation. Upon conclusion of the measurement period or final determination of the values of the assets acquired and liabilities assumed, whichever comes first, any subsequent adjustments will be recorded to the consolidated statement of operations. (z) Segment Information The Company's Chief Executive Officer is the chief operating decision maker, who reviews the Company's financial information presented on a consolidated basis for purposes of allocating resources and evaluating the Company's financial performance. Accordingly, the Company has determined that it operates in a single reporting segment. (aa) Fair Value of Financial Instruments The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value, and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows: • Level 1 Inputs: Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. • Level 2 Inputs: Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. • Level 3 Inputs: Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at measurement date. A financial instrument's categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company applies fair value accounting for all financial instruments on a recurring basis. The Company's financial instruments, which include cash, restricted cash, cash equivalents, accounts receivable and accounts payable are recorded at their carrying amounts, which approximate their fair values due to their short-term nature. Marketable securities consist of U.S. treasury securities, non-U.S government securities, high credit quality corporate debt securities and commercial paper. All marketable securities are considered to be available-for-sale and recorded at their estimated fair values. Unrealized gains and 91 Table of Contents losses for available-for-sale securities are recorded in other comprehensive loss. In valuing these items, the Company uses inputs and assumptions that market participants would use to determine their fair value, utilizing valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value of the senior notes due 2031 and 2029 (“2029 Notes” and “2031 Notes,” respectively) and the fair value of the convertible senior notes due 2023 (the “Convertible Notes” fully redeemed in 2021) are determined based on their respective closing prices on the last trading day of the reporting period and are classified as Level 2 in the fair value hierarchy. The carrying value of the strategic investments, which consist of restricted equity securities of a publicly held company and equity securities of privately held companies, is determined under the measurement alternative on a non-recurring basis adjusting for observable changes in fair value. The Company does not have a controlling interest nor can it exercise significant influence over any of these entities. The Company regularly reviews changes to the rating of its debt securities by rating agencies and monitors the surrounding economic conditions to assess the risk of expected credit losses. As of December 31, 2021, the risk of expected credit losses was not significant. Impairments are considered to be other than temporary if they are related to deterioration in credit risk or if it is likely that the security will be sold before the recovery of its cost basis. Realized gains and losses and declines in value deemed to be other than temporary are determined based on the specific identification method and are reported in other (expenses) income, net. (ab) Recently Issued Accounting Guidance, Not yet Adopted In October 2021, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2021-08, “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers,” which requires that an entity recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with ASC 606, "Revenue from Contracts with Customers". At the acquisition date, an acquirer should account for the related revenue contracts as if it had originated the contracts. Generally, this should result in an acquirer recognizing and measuring the acquired contact assets and contract liabilities consistent with how they were recognized and measured in the acquiree's financial statements, assuming the acquirer is able to assess and rely on how the acquiree applied ASC 606. ASU 2021-08 is effective for interim and annual periods beginning after December 15, 2022, with early adoption permitted. The Company expects to adopt ASU 2021-08 in the first quarter of 2022 with no material impact on the Company's consolidated financial statements. 3. Fair Value Measurements Financial Assets The following tables provide the financial assets measured at fair value on a recurring basis: Amortized Cost or Carrying Value Gross Unrealized Gains Gross Unrealized Losses Fair Value Hierarchy as of December 31, 2021 Aggregate Fair Value Level 1 Level 2 Level 3 Financial Assets: (In thousands) Cash and cash equivalents: Money market funds $ 786,548 $ — $ — $ 786,548 $ — $ — $ 786,548 Commercial paper 46,076 — — — 46,076 — 46,076 Total included in cash and cash equivalents 832,624 — — 786,548 46,076 — 832,624 Marketable securities: U.S. Treasury securities 375,305 6 ( 2,561 ) 372,750 — — 372,750 Non-U.S. government securities 221,641 — ( 1,355 ) 220,286 — — 220,286 Corporate debt securities and commercial paper 3,300,326 960 ( 15,892 ) 31,000 3,254,394 — 3,285,394 Total marketable securities 3,897,272 966 ( 19,808 ) 624,036 3,254,394 — 3,878,430 Total financial assets $ 4,729,896 $ 966 $ ( 19,808 ) $ 1,410,584 $ 3,300,470 $ — $ 4,711,054 92 Table of Contents Amortized Cost or Carrying Value Gross Unrealized Gains Gross Unrealized Losses Fair Value Hierarchy as of December 31, 2020 Aggregate Fair Value Level 1 Level 2 Level 3 Financial Assets: (In thousands) Cash and cash equivalents: Money market funds $ 656,749 $ — $ — $ 656,749 $ — $ — $ 656,749 Commercial paper 2,000 — — — 2,000 — 2,000 Total included in cash and cash equivalents 658,749 — — 656,749 2,000 — 658,749 Marketable securities: U.S. Treasury securities 223,247 389 ( 1 ) 223,635 — — 223,635 Corporate debt securities and commercial paper 1,874,257 8,149 ( 135 ) 50,000 1,832,271 — 1,882,271 Total marketable securities 2,097,504 8,538 ( 136 ) 273,635 1,832,271 — 2,105,906 Total financial assets $ 2,756,253 $ 8,538 $ ( 136 ) $ 930,384 $ 1,834,271 $ — $ 2,764,655 The Company's primary objective when investing excess cash is preservation of capital, hence the Company's marketable securities primarily consist of U.S. Treasury Securities, non-U.S government securities, high credit quality corporate debt securities and commercial paper. As the Company views its marketable securities as available to support current operations, it has classified all available for sale securities as short-term. As of December 31, 2021 and 2020, for fixed income securities that were in unrealized loss positions, the Company has determined that (i) it does not have the intent to sell any of these investments, and (ii) it is not more likely than not that it will be required to sell any of these investments before recovery of the entire amortized cost basis. In addition, as of December 31, 2021 and 2020, the Company anticipates that it will recover the entire amortized cost basis of such fixed income securities before maturity. Interest earned on marketable securities was $ 55.7 million, $ 32.4 million and $ 20.8 million in the years ended December 31, 2021, 2020 and 2019, respectively. The interest is recorded as other (expenses) income, net, in the accompanying consolidated statements of operations. The following table summarizes the contractual maturities of marketable securities: As of December 31, 2021 As of December 31, 2020 Amortized Cost Aggregate Fair Value Amortized Cost Aggregate Fair Value Financial Assets: (In thousands) Less than one year $ 1,084,751 $ 1,085,006 $ 1,126,091 $ 1,128,927 One to three years 2,812,521 2,793,424 971,413 976,979 Total $ 3,897,272 $ 3,878,430 $ 2,097,504 $ 2,105,906 Strategic Investments As of December 31, 2021 and 2020, the Company held strategic investments with a carrying value of $ 68.3 million and $ 9.3 million, respectively. These securities are recorded as other long-term assets in the accompanying consolidated balance sheets. There were no impairments or other adjustments recorded in the years ended December 31, 2021 and 2020 related to these securities. Financial Liabilities The Company’s financial liabilities that are measured at fair value on a recurring basis consist of foreign currency derivative liabilities and are classified as Level 2 financial instruments in the fair value hierarchy. As of December 31, 2021, the aggregate fair value of these instruments and the associated gross unrealized losses were not significant. The Company’s financial liabilities that are not measured at fair value on a recurring basis consist of its 2029 Notes and 2031 Notes, respectively. The Company’s Convertible Notes were fully redeemed in June 2021 and were no longer outstanding as of December 31, 2021. Refer to Note 10 for further details on these financial liabilities. As of December 31, 2021 the fair values of the 2029 Notes and 2031 Notes were $ 510.2 million and $ 512.8 million, respectively. As of December 31, 2020, the fair value of the Convertible Notes was $ 1.7 billion. 93 Table of Contents 4. Property and Equipment Property and equipment consisted of the following: As of December 31, 2021 2020 (In thousands) Capitalized internal-use software development costs $ 198,589 $ 142,489 Data center equipment (1) 77,946 43,477 Leasehold improvements 85,297 69,756 Office equipment 58,636 35,346 Furniture and fixtures 15,360 12,312 Software 10,506 9,943 Total property and equipment 446,334 313,323 Less: accumulated depreciation and amortization (1) ( 191,018 ) ( 130,084 ) Total property and equipment, net $ 255,316 $ 183,239 ____________________________________ ( 1 ) Data center equipment contains $ 63.0 million and $ 40.8 million in assets held under finance leases as of December 31, 2021 and 2020 , respectively. Accumulated depreciation and amortization contains $ 26.8 million and $ 15.0 million in accumulated amortizations for assets held under finance leases as of December 31, 2021 and 2020 , respectively. Depreciation and amortization expense was $ 59.6 million, $ 51.1 million and $ 37.5 million for the years ended December 31, 2021, 2020 and 2019, respectively. The Company capitalized $ 63.1 million, $ 47.1 million and $ 29.7 million in internal‑use software development costs in the years ended December 31, 2021, 2020 and 2019, respectively. 5. Derivatives and Hedging As of December 31, 2021, the Company had outstanding foreign currency forward contracts designated as cash flow hedges with total sell and buy notional values of $ 276.2 million and $ 243.1 million, respectively. The notional value represents the amount that will be purchased or sold upon maturity of the forward contract. As of December 31, 2021, these contracts had maturities of less than 12 months. Gains and losses associated with these foreign currency forward contracts were as follows: Consolidated Statement of Operations and Statement of Comprehensive Loss Year Ended December 31, 2021 (In thousands) Gains recognized in OCI Net change in market value of effective foreign currency forward exchange contracts $ 294 Losses recognized in income due to instruments maturing Cost of revenue $ 7,545 The Company is subject to master netting agreements with certain counterparties of the foreign exchange contracts, under which it is permitted to net settle transactions of the same currency with a single net amount payable by one party to the other. It is the Company’s policy to present the derivatives at gross in its consolidated balance sheet. The Company’s foreign currency forward contracts are not subject to any credit contingent features or collateral requirements. The Company manages its exposure to counterparty risk by entering into contracts with a diversified group of major financial institutions and by actively monitoring its outstanding positions. As of December 31, 2021, the Company did not have any offsetting arrangements. 94 Table of Contents 6. Right-of-Use Assets and Lease Liabilities The Company has entered into various operating lease agreements for office space and data centers and finance lease agreements for data center and office equipment and furniture. As of December 31, 2021, the Company had 31 leased properties with remaining lease terms of 0.1 years to 7.8 years, some of which include options to extend the leases for up to 5.0 years. Operating lease costs recorded in the accompanying consolidated statements of operations were $ 61.0 million and $ 49.3 million for the year ended December 31, 2021 and 2020, respectively. Short-term lease, variable lease and finance lease costs were not significant. Supplemental cash flow and other information related to operating leases was as follows: Year Ended December 31, 2021 2020 Operating cash flows paid for amounts included in operating lease liabilities (in thousands) $ 60,085 $ 46,895 Weighted average remaining lease term (in years) 5.5 6.0 Weighted average discount rate 4.5 % 4.8 % Maturities of operating lease liabilities were as follows: As of December 31, 2021 Year Ended December 31, (In thousands) 2022 $ 63,086 2023 57,173 2024 50,742 2025 37,621 2026 34,827 Thereafter 54,760 Total lease payments 298,209 Less: imputed interest ( 34,631 ) Total operating lease obligations 263,578 Less: current obligations ( 52,325 ) Long-term operating lease obligations $ 211,253 7. Business Combinations Zipwhip, Inc. In July 2021, the Company acquired all outstanding shares of Zipwhip, Inc. (“Zipwhip”), a leading provider of toll-free messaging in the United States, for a purchase price, as adjusted, of $ 838.8 million. The purchase price included $ 418.1 million of cash, $ 419.2 million fair value of 1.1 million shares of the Company's Class A common stock and $ 1.5 million fair value of the pre-combination services of Zipwhip employees reflected in the unvested equity awards assumed by the Company at closing. Additionally, at closing, the Company issued 59,533 shares of its Class A common stock which are subject to vesting over a period of 3 years. Vesting of these shares will be recorded in the stock-based compensation expense as the services are provided.. Part of the cash consideration paid at closing was to settle the vested equity awards of Zipwhip employees. The Company assumed all unvested and outstanding equity awards of Zipwhip continuing employees, as converted into its own equity awards, at the conversion ratio provided in the Agreement and Plan of Merger and Reorganization (the “Zipwhip Merger Agreement”). This transaction also included a $ 19.1 million of additional cash consideration for certain employees, which will vest as these employees provide services in the post-acquisition period. This amount will be recorded in the operating expenses over a period of 3 years as the services are provided. The acquisition was accounted for as a business combination and the total purchase price of $ 838.8 million was allocated to the net tangible and intangible assets and liabilities based on their fair values on the acquisition date with the excess recorded 95 Table of Contents as goodwill. These estimates were derived from information currently available. The determination of the fair values and estimated lives of depreciable tangible and identifiable intangible assets requires significant judgment. As of December 31, 2021, the areas that are not yet finalized include contingencies and income and other taxes. The fair value of the 1.2 million aggregate number of shares of the Company's Class A common stock issued at closing was determined based on the closing market price of the Company's Class A common stock on the acquisition date. The fair value of the $ 30.7 million unvested equity awards assumed on the acquisition closing date was determined (a) for options, by using the Black-Scholes option pricing model with the applicable assumptions as of the acquisition date; (b) for restricted stock units, by using the closing market price of the Company's Class A common stock on the acquisition date. These awards will continue to vest as Zipwhip employees continue to provide services in the post-acquisition period. The fair value of these awards will be recorded into the stock-based compensation expense over the respective vesting period of each award. The purchase price components, as adjusted, are summarized in the following table: Total (In thousands) Fair value of Class A common stock transferred $ 419,197 Cash consideration 418,073 Fair value of the pre-combination service through equity awards 1,511 Total purchase price $ 838,781 The following table presents the purchase price allocation, as adjusted, recorded in the Company's consolidated balance sheet as of December 31, 2021: Total (In thousands) Cash and cash equivalents $ 21,610 Accounts receivable and other current assets 11,481 Property and equipment, net 2,950 Operating right-of-use asset 23,545 Intangible assets (1) 244,500 Other assets 370 Goodwill 600,403 Accounts payable and other liabilities ( 20,239 ) Deferred revenue ( 4,526 ) Operating lease liability, noncurrent ( 23,169 ) Deferred tax liability ( 18,144 ) Total purchase price $ 838,781 ____________________________________ ( 1 ) Identifiable intangible assets are comprised of the following: Total Estimated life (In thousands) (In years) Developed technology $ 56,800 7 Customer relationships 147,700 10 Supplier relationships 39,600 5 Trade names 400 5 Total intangible assets acquired $ 244,500 Goodwill generated from this acquisition primarily represents the value that is expected from the increased scale and synergies as a result of the integration of both businesses. Goodwill is not deductible for tax purposes. 96 Table of Contents The estimated fair value of the intangible assets acquired was determined by the Company. The Company engaged a third‑party expert to assist with the valuation analysis. The Company used a relief-from-royalty method to estimate the fair values of the developed technology and trade names, a multi-period excess earnings method to estimate the fair values of customer relationships and a with-and-without method to estimate the fair value of the supplier relationships. Most of the net tangible assets were valued at their respective carrying amounts as of the acquisition date as the Company believes that these amounts approximate their current fair values, except for operating right-of-use assets. The value of the acquired operating right-of-use assets was reduced to its respective fair value on the acquisition date. The acquired entity's results of operations were included in the Company's consolidated financial statements from the date of acquisition, July 14, 2021. For the year ended December 31, 2021, Zipwhip contributed net operating revenue of $ 55.4 million, which is reflected in the accompanying consolidated statement of operations. Due to the integrated nature of the Company's operations, the Company believes that it is not practicable to separately identify earnings of Zipwhip on a stand-alone basis. Pro forma results of operations for this acquisition are not presented as the financial impact to the Company's consolidated financial statements is not significant. Costs incurred related to the acquisition were not significant. Other Fiscal 2021 Acquisitions During 2021, the Company completed other business combinations for an aggregate purchase price of $ 105.0 million, of which $ 13.4 million was allocated to developed technology, $ 23.6 million was allocated to other intangible assets and $ 63.2 million was allocated to goodwill. Fiscal 2020 Acquisitions Segment.io, Inc. In November 2020, the Company acquired all outstanding shares of Segment, the market-leading customer data platform, by issuing 9.5 million shares of its Class A common stock with a fair value of $ 2.6 billion and $ 415.9 million in cash, as adjusted. Of the total shares of Class A common stock issued at closing, 258,554 shares with the fair value of $ 70.7 million were subject to future vesting and are recorded in the stock-based compensation expense as the services are provided. The total amortization period was over 2.41 years from the date of acquisition. Part of the cash consideration was paid to settle the vested equity awards of Segment employees. The Company assumed all unvested and outstanding equity awards of Segment continuing employees as converted into its own equity awards at the conversion ratio provided in the Agreement and Plan of Reorganization (the "Merger Agreement"). The acquisition added additional products and services to the Company's offerings for its customers. With these additional products, the Company can now offer a customer engagement platform. The acquisition has also added new customers, new employees, technology and intellectual property assets. The acquisition was accounted for as a business combination and the total purchase price of $ 3.0 billion, as adjusted, was allocated to the net tangible and intangible assets and liabilities based on their fair values on the acquisition date with the excess recorded as goodwill. The purchase price, as adjusted, reflected the $ 2.5 billion fair value of 9.3 million shares of the Company's Class A common stock transferred as consideration for accredited outstanding shares of Segment, the $ 415.9 million cash consideration for unaccredited shares and vested equity awards and the $ 39.0 million fair value of the pre-combination services of Segment employees reflected in the unvested equity awards assumed by the Company on the acquisition date. As of December 31, 2021, 150,824 shares of Class A common stock issued at closing with future vesting was held in escrow. The fair value of the 9.5 million shares of the Company's Class A common stock issued at closing was determined based on its closing price on the acquisition date. The fair value of the assumed unvested equity awards was determined (a) for options, by using a Black-Scholes option pricing model with the applicable assumptions as of the acquisition date, and (b) for restricted stock units, by using the closing market price of the Company's Class A common stock on the acquisition date. The fair value of unvested employee equity awards assumed on the acquisition date was $ 245.3 million. These awards continue to vest as the Segment employees provide services in the post-acquisition period. The fair value of these awards is 97 Table of Contents recorded in the stock-based compensation expense over the respective vesting period of each award. The purchase price components, as adjusted, are summarized in the following table: Total (In thousands) Fair value of Class A common stock transferred $ 2,532,329 Cash consideration 415,899 Fair value of the pre-combination service through equity awards 38,972 Total purchase price $ 2,987,200 The following table presents the purchase price allocation, as adjusted: Total (In thousands) Cash and cash equivalents $ 93,170 Accounts receivable and other current assets 90,635 Property and equipment, net 5,081 Operating right-of-use asset 53,630 Intangible assets (1) 595,000 Other assets 4,869 Goodwill 2,299,016 Accounts payable and other liabilities ( 24,263 ) Deferred revenue ( 50,005 ) Operating lease liability ( 58,206 ) Deferred tax liability ( 21,728 ) Total purchase price $ 2,987,200 ____________________________________ ( 1 ) Identifiable intangible assets are comprised of the following: Total Estimated life (In thousands) (In years) Developed technology $ 390,000 7 Customer relationships 190,000 6 Order backlog 10,000 1 Trade names 5,000 5 Total intangible assets acquired $ 595,000 Developed technology consists of software products and domain knowledge around customer data developed by Segment, which will enable Twilio to layer data across its platform to power timely and personalized communications over the right channel, further enhancing the Company's customer engagement platform. Customer relationships consists of contracts with platform users that purchase Segment’s products and services that carry distinct value. Goodwill generated from this acquisition primarily represents the value that is expected from the increased scale and synergies as a result of the integration of both businesses. Goodwill is not deductible for tax purposes. The estimated fair value of the intangible assets acquired was determined by the Company. The Company engaged a third‑party expert to assist with the valuation analysis. The Company used a relief from royalty method to estimate the fair values of the developed technology and a multi-period excess earnings method to estimate the fair value of the customer relationships and order backlog. 98 Table of Contents Most of the net tangible assets were valued at their respective carrying amounts as of the acquisition date, as the Company believes that these amounts approximate their current fair values, except for operating right-of-use assets, which were reduced to their respective fair values as of the acquisition date. The acquired entity's results of operations were included in the Company's consolidated financial statements from the date of acquisition, November 2, 2020. For the year ended December 31, 2021, Segment contributed net operating revenue of $ 200.9 million, which is reflected in the accompanying consolidated statement of operations. Due to the integrated nature of the Company's operations, the Company believes that it is not practicable to separately identify earnings of Segment on a stand-alone basis. During the year ended December 31, 2020, the Company incurred costs related to this acquisition of $ 20.8 million that were expensed as incurred and recorded in general and administrative expenses in the accompanying consolidated statement of operations. The following unaudited pro forma condensed combined financial information gives effect to the acquisition of Segment as if it was consummated on January 1, 2019 (the beginning of the comparable prior reporting period), and includes pro forma adjustments related to the amortization of acquired intangible assets, share-based compensation expense, one-time tax benefit and direct and incremental transaction costs reflected in the historical financial statements. Specifically, the following adjustments were made: • For the year ended December 31, 2020, the Company's and Segment's direct and incremental transaction costs of $ 79.3 million are excluded from the pro forma condensed combined net loss. • For the year ended December 31, 2019, the Company's direct and incremental transaction costs of $ 20.8 are included in the pro forma condensed combined net loss. • In the year ended December 31, 2020, the pro forma condensed combined net loss includes a reversal of the valuation allowance release of $ 13.8 million. • In the year ended December 31, 2019, the pro forma condensed combined net loss includes a one-time tax benefit of $ 38.1 that would have resulted from the acquisition, and an ongoing tax benefit of $ 7.5 million. This unaudited data is presented for informational purposes only and is not intended to represent or be indicative of the results of operations that would have been reported had the acquisition occurred on January 1, 2019. It should not be taken as representative of future results of operations of the combined company. The following table presents the unaudited pro forma condensed combined financial information: Year Ended December 31, 2020 2019 (Unaudited, in thousands) Revenue $ 1,874,720 $ 1,217,502 Net loss attributable to common stockholders $ ( 655,355 ) $ ( 576,962 ) Other Fiscal 2020 Acquisitions During 2020, the Company completed other business combinations for an aggregate purchase price of $ 13.0 million. The total purchase price was allocated to the tangible and intangibles assets acquired and liabilities assumed based on their fair values at the time of the acquisition. The Company does not consider these acquisitions to be material, individually or in aggregate, to its consolidated financial statements. 99 Table of Contents 8. Goodwill and Intangible Assets Goodwill Goodwill balance as of December 31, 2021 and 2020, was as follows: Total (In thousands) Balance as of December 31, 2019 $ 2,296,784 Goodwill additions related to 2020 acquisitions 2,303,780 Measurement period adjustments ( 5,170 ) Balance as of December 31, 2020 $ 4,595,394 Goodwill additions related to 2021 acquisitions 663,599 Measurement period adjustments 4,173 Balance as of December 31, 2021 $ 5,263,166 Intangible assets Intangible assets consisted of the following: As of December 31, 2021 Gross Accumulated Amortization Net Amortizable intangible assets: (In thousands) Developed technology $ 794,831 $ ( 222,765 ) $ 572,066 Customer relationships 538,264 ( 128,035 ) 410,229 Supplier relationships 51,671 ( 9,491 ) 42,180 Trade names 30,669 ( 13,874 ) 16,795 Order backlog 10,000 ( 10,000 ) — Patent 4,035 ( 508 ) 3,527 Total amortizable intangible assets 1,429,470 ( 384,673 ) 1,044,797 Non-amortizable intangible assets: Telecommunication licenses 4,920 — 4,920 Trademarks and other 295 — 295 Total $ 1,434,685 $ ( 384,673 ) $ 1,050,012 100 Table of Contents As of December 31, 2020 Gross Accumulated Amortization Net Amortizable intangible assets: (In thousands) Developed technology $ 724,599 $ ( 113,282 ) $ 611,317 Customer relationships 379,344 ( 59,574 ) 319,770 Supplier relationships 4,356 ( 3,044 ) 1,312 Trade names 25,560 ( 7,921 ) 17,639 Order backlog 10,000 ( 1,667 ) 8,333 Patent 3,360 ( 373 ) 2,987 Total amortizable intangible assets 1,147,219 ( 185,861 ) 961,358 Non-amortizable intangible assets: Telecommunication licenses 4,920 — 4,920 Trademarks and other 295 — 295 Total $ 1,152,434 $ ( 185,861 ) $ 966,573 Amortization expense was $ 198.8 million, $ 98.6 million and $ 72.9 million for the years ended December 31, 2021, 2020 and 2019, respectively. Total estimated future amortization expense is as follows: As of December 31, 2021 Year Ended December 31, (In thousands) 2022 $ 204,837 2023 201,527 2024 195,953 2025 192,379 2026 119,045 Thereafter 131,056 Total $ 1,044,797 9. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following: As of December 31, 2021 2020 (In thousands) Accrued payroll and related $ 78,780 $ 54,683 Accrued bonus and commission 64,665 25,341 Accrued cost of revenue 118,004 80,620 Sales and other taxes payable 61,975 48,390 ESPP contributions 10,284 6,272 Finance lease liability, current 12,370 9,062 Accrued other expense 71,425 28,527 Total accrued expenses and other current liabilities $ 417,503 $ 252,895 101 Table of Contents 10. Notes Payable Long-term debt consisted of the following: As of December 31, 2021 2020 (In thousands) 2029 and 2031 Senior Notes 2029 Senior Notes Principal $ 500,000 $ — Unamortized discount ( 5,701 ) — Unamortized issuance costs ( 1,286 ) — Net carrying amount 493,013 — 2031 Senior Notes Principal 500,000 — Unamortized discount ( 5,832 ) — Unamortized issuance costs ( 1,274 ) — Net carrying amount 492,894 — Convertible Senior Notes and Capped Call Transactions Convertible Senior Notes Principal — 343,702 Unamortized discount — ( 38,406 ) Unamortized issuance costs — ( 3,228 ) Net carrying amount — 302,068 Total long-term debt $ 985,907 $ 302,068 2029 and 2031 Senior Notes In March 2021, the Company issued $ 1.0 billion aggregate principal amount of senior notes, consisting of $ 500.0 million principal amount of 3.625 % notes due 2029 (the “2029 Notes”) and $ 500.0 million principal amount of 3.875 % notes due 2031 (the “2031 Notes,” and together with the 2029 Notes, the “Notes”). Initially, none of the Company’s subsidiaries guaranteed the Notes. However, under certain circumstances in the future the Notes can be guaranteed by each of the Company’s material domestic subsidiaries. The 2029 Notes and 2031 Notes will mature on March 15, 2029 and March 15, 2031, respectively. Interest payments are payable semi-annually in arrears on March 15 and September 15 of each year, commencing on September 15, 2021. The aggregate net proceeds from offering of the Notes were approximately $ 984.7 million after deducting underwriting discounts and issuance costs paid by the Company. The issuance costs of $ 2.8 million are amortized into interest expense using the effective interest method over the term of the Notes. 102 Table of Contents The Company may voluntarily redeem the 2029 Notes, in whole or in part, under the following circumstances: (1) at any time prior to March 15, 2024 with the net cash proceeds received by the Company from an equity offering at a redemption price equal to 103.625 % of the principal amount, provided the aggregate principal amount of all such redemptions does not exceed 40 % of the original aggregate principal amount of the 2029 Notes. Such redemption shall occur within 180 days after the closing of an equity offering and at least 50 % of the then-outstanding aggregate principal amount of the 2029 Notes shall remain outstanding, unless all 2029 Notes are redeemed concurrently; (2) at any time prior to March 15, 2024 at 100 % of the principal amount, plus a “make-whole” premium; (3) at any time on or after March 15, 2024 at a prepayment price equal to 101.813 % of the principal amount; (4) at any time on or after March 15, 2025 at a prepayment price equal to 100.906 % of the principal amount; and (5) at any time on or after March 15, 2026 at a prepayment price equal to 100.000 % of the principal amount; in each case, the redemption will include the accrued and unpaid interest, as applicable. The Company may voluntarily redeem the 2031 Notes, in whole or in part, under the following circumstances: (1) at any time prior to March 15, 2024 with the net cash proceeds received by the Company from an equity offering at a redemption price equal to 103.875 % of the principal amount, provided the aggregate principal amount of all such redemptions does not to exceed 40 % of the original aggregate principal amount of the 2031 Notes. Such redemption shall occur within 180 days after the closing of an equity offering and at least 50 % of the then-outstanding aggregate principal amount of the 2031 Notes shall remain outstanding, unless all 2031 Notes are redeemed concurrently; (2) at any time prior to March 15, 2026 at 100 % of the principal amount, plus a “make-whole” premium; (3) at any time on or after March 15, 2026 at a prepayment price equal to 101.938 % of the principal amount; (4) at any time on or after March 15, 2027 at a prepayment price equal to 101.292 % of the principal amount; (5) at any time on or after March 15, 2028 at a prepayment price equal to 100.646 % of the principal amount; and (6) at any time on or after March 15, 2029 at a prepayment price equal to 100.000 % of the principal amount; in each case, the redemption will include accrued and unpaid interest, as applicable. The Notes are unsecured obligations and will rank senior in right of payment to any of the Company’s indebtedness that is expressly subordinated in right of payment to the Notes that the Company may incur in the future and equal in right of payment with the Company’s existing and future liabilities that are not subordinated. In certain circumstances involving a change of control event, the Company will be required to make an offer to repurchase all, or, at the holder’s option, any part, of each holder’s notes of that series at 101 % of the aggregate principal amount, plus accrued and unpaid interest, as applicable. The indenture governing the Notes (the “Indenture”) contains covenants limiting the Company’s ability and the ability of its subsidiaries to: (i) create liens on certain assets to secure debt; (ii) grant a subsidiary guarantee of certain debt without also providing a guarantee of the Notes; and (iii) consolidate or merge with or into, or sell or otherwise dispose of all or substantially all of its assets to another person. These covenants are subject to a number of limitations and exceptions. Certain of these covenants will not apply during any period in which the Notes are rated investment grade by either Moody’s Investors Service, Inc. or Standard & Poor’s Ratings Services. 103 Table of Contents The interest expense recognized during the year ended December 31, 2021 was not significant. As of December 31, 2021, the Company was in compliance with all of its financial covenants under the Indenture. Convertible Senior Notes and Capped Call Transactions In May 2018, the Company issued $ 550.0 million aggregate principal amount of 0.25 % convertible senior notes due 2023 (“Convertible Notes”) in a private placement, including $ 75.0 million aggregate principal amount of such Convertible Notes pursuant to the exercise in full of the over-allotment options of the initial purchasers. The total net proceeds from this offering, after deducting initial purchaser discounts and debt issuance costs paid by the Company, were approximately $ 537.0 million. The Convertible Notes had the original maturity date of June 1, 2023, unless earlier repurchased or redeemed by the Company or converted pursuant to their terms. On May 18, 2021, the Company issued a notice of redemption for its Convertible Notes and in June 2021, redeemed all of the remaining outstanding principal amount of the Convertible Notes. During 2021 and through the date of the redemption, the Company converted $ 343.7 million aggregate principal amount of the Convertible Notes by issuing 4,846,965 shares of its Class A common stock. Of the $ 1.7 billion total value of these transactions, $ 1.4 billion and $ 335.7 million were allocated to the equity and liability components, respectively, utilizing the effective interest rate to determine the fair value of the liability component. The selected interest rate reflected the Company’s incremental borrowing rate, adjusted for the Company’s credit standing on nonconvertible debt with similar maturity. The extinguishment of these Convertible Notes resulted in a $ 29.0 million loss that is included in other (expenses) income, net, in the accompanying consolidated statement of operations. No sinking fund was provided for these Convertible Notes. In the year ended December 31, 2020, the Company converted $ 206.3 million aggregate principal amount of the Convertible Notes by issuing 2,902,434 shares of its Class A common stock and $ 2.0 million of cash. Of the $ 894.6 million total value of these transactions, $ 701.9 million and $ 192.7 million were allocated to the equity and liability components, respectively. The extinguishment of these notes resulted in a $ 12.9 million loss and was included in other (expenses) income, net, in the accompanying consolidated statements of operations. There were no conversions in the year ended December 31, 2019. Prior to their redemption, the Convertible Notes were convertible at the option of the holders only under the following circumstances: (1) during any calendar quarter commencing after September 30, 2018, and only during such calendar quarter, if the last reported sale price of the Class A common stock for at least 20 trading days (whether or not consecutive) in a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is more than or equal to 130 % of the conversion price on each applicable trading day; (2) during the five business days period after any five consecutive trading day period in which, for each trading day of that period, the trading price per $1,000 principal amount of Convertible Notes for such trading day was less than 98 % of the product of the last reported sale price of the Class A common stock and the conversion rate on each such trading day; (3) upon the Company’s notice that it is redeeming any or all of the Convertible Notes; or (4) upon the occurrence of specified corporate events. Each $1,000 principal amount of the Convertible Notes was initially convertible into 14.104 shares of the Company’s Class A common stock par value $ 0.001 , which was equivalent to an initial conversion price of approximately $ 70.90 per share. The conversion rate was subject to adjustment upon the occurrence of certain specified events but would not be adjusted for any accrued and unpaid special interest. In addition, upon the occurrence of a make-whole fundamental change, as defined in the indenture, the Company would, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its Notes in connection with such make-whole fundamental change or during the relevant redemption period. Further, the Convertible Notes could bear special interest under specified circumstances relating to the Company’s failure to comply with its reporting obligations under the indenture relating to the issuance of Convertible Notes (the “indenture”) or if the Convertible Notes were not freely tradeable as required by the indenture. None of the above mentioned events occurred during the period the notes were outstanding and prior to the redemption. 104 Table of Contents Upon conversion, the Company had an ability to pay or deliver, as the case may be, cash, shares of Class A common stock, or a combination of cash and shares of Class A common stock, at the Company’s election. Throughout the period the Convertible Notes were outstanding the conditional redemption feature was triggered several times and the Company settled the notes presented for conversion primarily in shares of its Class A common stock. The foregoing description is qualified in its entirety by reference to the text of the indenture and the form of 0.25 % convertible senior notes due 2023, which were filed as exhibits to the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2018, and are incorporated herein by reference. In accounting for the issuance of the Convertible Notes, the Company separated the Convertible Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was $ 119.4 million and was determined by deducting the fair value of the liability component from the par value of the Notes. The equity component was not remeasured as long as it continued to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount, or the debt discount, was amortized to interest expense at an annual effective interest rate of 5.7 % over the contractual terms of the Convertible Notes. In accounting for the transaction costs related to the Convertible Notes, the Company allocated the total amount incurred to the liability and equity components of the Convertible Notes based on the proportion of the proceeds allocated to the debt and equity components. Issuance costs attributable to the liability component were approximately $ 10.2 million, were recorded as an additional debt discount and were amortized to interest expense using the effective interest method over the contractual terms of the Convertible Notes and were written off upon the redemption of the Convertible Notes. Issuance costs attributable to the equity component were netted with the equity component in stockholders’ equity. The net carrying amount of the equity component of the Convertible Notes was as follows: As of December 31, 2021 2020 (In thousands) Proceeds allocated to the conversion options (debt discount) $ — $ 74,636 Issuance costs ( 2,819 ) ( 2,819 ) Net carrying amount $ ( 2,819 ) $ 71,817 In connection with the offering of the Convertible Notes in May 2018, the Company entered into privately negotiated capped call transactions with certain counterparties (the “capped calls”). The capped calls each had an initial strike price of approximately $ 70.90 per share, subject to certain adjustments, which corresponded to the initial conversion price of the Notes. The capped calls had initial cap prices of $ 105.04 per share, subject to certain adjustments. The capped calls covered, subject to anti-dilution adjustments, approximately 7,757,200 shares of Class A common stock. The capped calls were generally intended to reduce or offset the potential dilution to the Class A common stock upon any conversion of the Notes with such reduction or offset, as the case may be, subject to a cap based on the cap price. Concurrently with the redemption of the Convertible Notes, the Company settled its capped call arrangement. The capped call arrangement was settled in June 2021 for gross cash consideration of $ 229.8 million received by the Company and recorded in additional paid-in-capital, net of $ 1.4 million in transaction costs and a $ 3.2 million realized gain. The gain was primarily driven by the change in the fair value of the Company’s Class A common stock on the transaction settlement date. The gain was recorded in other (expenses) income, net, in the accompanying consolidated statement of operations. 105 Table of Contents 11. Supplemental Balance Sheet Information A roll‑forward of the Company’s customer credit reserve is as follows: Year Ended December 31, 2021 2020 2019 (In thousands) Balance, beginning of period $ 16,783 $ 6,784 $ 3,015 Additions 55,937 50,817 18,143 Deductions against reserve ( 54,143 ) ( 40,818 ) ( 14,374 ) Balance, end of period $ 18,577 $ 16,783 $ 6,784 12. Revenue by Geographic Area Revenue by geographic area is based on the IP address or the mailing address at the time of registration. The following table sets forth revenue by geographic area: Year Ended December 31, 2021 2020 2019 Revenue by geographic area: (In thousands) United States $ 1,881,873 $ 1,282,213 $ 808,857 International 959,966 479,563 325,611 Total $ 2,841,839 $ 1,761,776 $ 1,134,468 Percentage of revenue by geographic area: United States 66 % 73 % 71 % International 34 % 27 % 29 % Long-lived assets outside of the United States were not significant. 13. Commitments and Contingencies (a) Lease and Other Commitments The Company entered into various non-cancelable operating lease agreements for its facilities. See Note 6 to these consolidated financial statements for additional detail on the Company's operating lease commitments. 106 Table of Contents Additionally, the Company has contractual commitments with its cloud infrastructure provider, network service providers and other vendors that are noncancellable and expire within one to four years . Future minimum payments under these noncancellable purchase commitments were as follows. Unrecognized tax benefits are not included in these amounts because any amounts expected to be settled in cash are not material: As of December 31, 2021 Year Ending December 31, (In thousands) 2022 $ 213,106 2023 222,852 2024 35,066 2025 561 Total payments $ 471,585 In February 2021, the Company entered into a Framework Agreement, as subsequently amended, with Syniverse Corporation (“Syniverse”) and Carlyle Partners V Holdings, L.P. (“Carlyle”) (the “Framework Agreement”), pursuant to which Syniverse would issue to the Company shares of Syniverse common stock in consideration for an investment by the Company of up to $ 750.0 million. In August 2021, Syniverse entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Blue Steel Merger Sub Inc. (the “Merger Sub”) and M-3 Brigade Acquisition II Corp. (“MBAC”), which would result in Syniverse being a wholly owned subsidiary of MBAC (the “Merger”). Concurrently, the Company and MBAC entered into the Twilio Subscription Agreement (the “Subscription Agreement”), pursuant to which the Company agreed, subject to the terms and conditions set forth therein, to subscribe for and purchase, and MBAC agreed to issue and sell to the Company, immediately prior to the closing of the Merger, shares of Class A common stock and, if applicable, shares of Class C common stock for an aggregate amount up to $ 750.0 million, depending on redemptions by MBAC’s shareholders. In connection with the closing of the investment, the Company and Syniverse (or their respective subsidiaries) would enter into a wholesale agreement. See Note 18 for details on developments on this transaction which occurred in the period subsequent to December 31, 2021. (b) Legal Matters The City and County of San Francisco (“San Francisco”) has assessed the Company for additional Telephone Users Tax (“TUT”) and Access Line Tax (“ALT”) on certain of the Company’s services for the years 2009 through 2018. The assessments totaled $ 38.8 million, including interest and penalties. The Company paid the assessments under protest in the third quarter of 2020. On May 27, 2021, the Company filed a lawsuit against San Francisco in San Francisco Superior Court challenging the assessments. The Company raised numerous defenses to the assessments including that its services are not telecommunications services, application of the taxes to Twilio’s services violates the Internet Tax Freedom Act and San Francisco does not have jurisdiction to impose tax on services provided outside of San Francisco. The Company is seeking refunds of the taxes paid, waivers of interest and penalties, cost of suit and reasonable attorneys’ fees, and other legal and equitable relief as the court deems appropriate. The Company believes it has strong arguments against the assessments, but litigation is uncertain and there is no assurance that it will prevail in court. Should the Company lose on one or more of its arguments, it could incur additional losses associated with taxes, interest, and penalties that together, in aggregate, could be material. The Company regularly assesses the likelihood of adverse outcomes resulting from tax disputes such as this and examines all open years to determine the necessity and adequacy of any tax reserves. The Company’s tax reserves are further discussed in Note 13(d) of these consolidated financial statements. 107 Table of Contents In addition to the litigation discussed above, from time to time, the Company may be subject to legal actions and claims in the ordinary course of business. The Company has received, and may in the future continue to receive, claims from third parties asserting, among other things, infringement of their intellectual property rights. Future litigation may be necessary to defend the Company, its partners and its customers by determining the scope, enforceability and validity of third‑party proprietary rights, or to establish our proprietary rights. The results of any current or future litigation cannot be predicted with certainty, and regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources, and other factors. Legal fees and other costs related to litigation and other legal proceedings are expensed as incurred and are included in general and administrative expenses in the accompanying consolidated statements of operations. (c) Indemnification Agreements The Company has signed indemnification agreements with all of its board members and executive officers. The agreements indemnify the board members and executive officers from claims and expenses on actions brought against the individuals separately or jointly with the Company for certain indemnifiable events. Indemnifiable events generally mean any event or occurrence related to the fact that the board member or the executive officer was or is acting in his or her capacity as a board member or an executive officer for the Company or was or is acting or representing the interests of the Company. In the ordinary course of business and in connection with our financing and business combinations transactions, the Company enters into contractual arrangements under which it agrees to provide indemnification of varying scope and terms to business partners, customers and other parties with respect to certain matters, including, but not limited to, losses arising out of the breach of such agreements, intellectual property infringement claims made by third parties and other liabilities relating to or arising from the Company’s various products, or its acts or omissions. In these circumstances, payment may be conditional on the other party making a claim pursuant to the procedures specified in the particular contract. Further, the Company’s obligations under these agreements may be limited in terms of time and/or amount, and in some instances, the Company may have recourse against third parties for certain payments. The terms of such obligations may vary. As of December 31, 2021 and 2020, no amounts were accrued related to any outstanding indemnification agreements. (d) Other Taxes The Company conducts operations in many tax jurisdictions within and outside the United States. In many of these jurisdictions, non-income-based taxes, such as sales, use, telecommunications, and other local taxes are assessed on the Company’s operations. In the last several years the Company has expanded to collect taxes in most jurisdictions where it operates. The Company continues to carry reserves for certain of its prior non-income-based tax exposures in certain jurisdictions when it is both probable that a liability was incurred and the amount of the exposure could be reasonably estimated. These reserves are based on estimates which include several key assumptions including, but not limited to, the taxability of the Company’s services, the jurisdictions in which its management believes it had nexus, and the sourcing of revenues to those jurisdictions The Company continues to remain in discussions with certain jurisdictions regarding its prior sales and other taxes that it may owe. In the event any of these jurisdictions disagree with management’s assumptions and analysis, the assessment of the Company’s tax exposure could differ materially from management’s current estimates. For example, San Francisco City and County has assessed the Company for $ 38.8 million in taxes, including interest and penalties, which exceeded the $ 11.5 million the Company had accrued for the period covered by this assessment. The Company paid the full amount as required by law. The payment made in excess of the accrued amount is reflected as a deposit in the accompanying consolidated balance sheets. The Company believes, however, that this assessment is incorrect and, after failing to reach a settlement, filed a lawsuit on May 27, 2021 contesting the assessment as described above. However, litigation is uncertain and a ruling against the Company, or a dismissal of our complaint, may adversely affect its financial position and results of operations. As of December 31, 2021, the liabilities recorded for these taxes were $ 25.4 million for domestic jurisdictions and $ 17.7 million for jurisdictions outside of the United States. As of December 31, 2020, these liabilities were $ 25.6 million and $ 9.6 million, respectively. 108 Table of Contents 14. Stockholders' Equity Preferred Stock As of December 31, 2021 and 2020, the Company had authorized 100,000,000 shares of preferred stock, par value $ 0.001 , of which no shares were issued and outstanding. Common Stock As of December 31, 2021 and 2020, the Company had authorized 1,000,000,000 shares of Class A common stock and 100,000,000 shares of Class B common stock, each par value $ 0.001 per share. As of December 31, 2021, 170,625,994 shares of Class A common stock and 9,842,105 shares of Class B common stock were issued and outstanding. As of December 31, 2020, 153,496,222 shares of Class A common stock and 10,551,302 shares of Class B common stock were issued and outstanding. The Company had reserved shares of common stock for issuance as follows: As of December 31, 2021 2020 Stock options issued and outstanding 3,351,313 5,625,735 Unvested restricted stock units issued and outstanding 6,475,700 7,523,882 Class A common stock reserved for Twilio.org 618,857 707,265 Stock-based awards available for grant under 2016 Plan 24,650,104 18,942,205 Stock-based awards available for grant under ESPP 6,382,830 4,941,281 Class A common stock reserved for the Convertible Notes — 7,569,731 Total 41,478,804 45,310,099 Public Equity Offerings In February 2021, August 2020 and June 2019, the Company completed public equity offerings in which it sold 4,312,500 shares, 5,819,838 shares and 8,064,515 shares, respectively, of its Class A common stock at a public offering price of $ 409.60 , $ 247.00 and $ 124.00 per share, respectively. The Company received total proceeds of $ 1.8 billion, $ 1.4 billion and $ 979.0 million, respectively, net of underwriting discounts and offering expenses paid by the Company. 15. Stock-Based Compensation 2008 Stock Option Plan The Company maintained a stock plan, the 2008 Stock Option Plan, as amended and restated (the “2008 Plan”), which allowed the Company to grant incentive (“ISO”), non‑statutory (“NSO”) stock options and restricted stock units (“RSU”) to its employees, directors and consultants to participate in the Company’s future performance through stock‑based awards at the discretion of the board of directors. Under the 2008 Plan, options to purchase the Company’s common stock could not be granted at a price less than fair value in the case of ISOs and NSOs. Fair value was determined by the board of directors, in good faith, with input from valuation consultants. On June 22, 2016, the plan was terminated in connection with the Company’s IPO. Accordingly, no shares are available for future issuance under the 2008 Plan. The 2008 Plan continues to govern outstanding equity awards granted thereunder. The Company’s right of first refusal for outstanding equity awards granted under the 2008 Plan terminated upon completion of the IPO. All remaining outstanding stock options granted under the 2008 Plan are vested and exercisable. 109 Table of Contents 2016 Stock Option Plan The Company’s 2016 Stock Option and Incentive Plan (the “2016 Plan”) became effective on June 21, 2016. The 2016 Plan provides for the grant of ISOs, NSOs, restricted stock, RSUs, stock appreciation rights, unrestricted stock awards, performance share awards, dividend equivalent rights and cash-based awards to employees, directors and consultants of the Company. A total of 11,500,000 shares of the Company’s Class A common stock were initially reserved for issuance under the 2016 Plan. These available shares automatically increase each January 1, beginning on January 1, 2017, by 5 % of the number of shares of the Company’s Class A and Class B common stock outstanding on the immediately preceding December 31, or such lesser number of shares as determined by the Company’s compensation committee. On January 1, 2021 and 2020, the shares available for grant under the 2016 Plan were automatically increased by 8,202,376 shares and 6,920,640 shares, respectively. Under the 2016 Plan, the stock options are granted at a price per share not less than 100 % of the fair market value per share of the underlying common stock on the date of grant. Segment 2013 Stock Incentive Plan In connection with its acquisition of Segment, the Company assumed and replaced all stock options and restricted stock units of continuing employees issued under Segment’s 2013 Stock Incentive Plan (“Segment Plan”) that were unvested and outstanding on the acquisition date. The assumed equity awards will continue to be outstanding and will be governed by the provisions of the Segment Plan. SendGrid 2009, 2012 and 2017 Stock Incentive Plans In connection with its acquisition of SendGrid, the Company assumed all stock options and restricted stock units issued under SendGrid’s 2009, 2012 and 2017 Stock Incentive Plans that were outstanding on the date of acquisition. The assumed equity awards will continue to be outstanding and will be governed by the provisions of their respective plans. Additionally, the Company assumed shares of SendGrid common stock that were reserved and available for issuance under SendGrid's 2017 Equity Incentive Plan, on an as converted basis. These shares can be utilized for future equity grants under the Company’s 2016 Plan, to the extent permitted by New York Stock Exchange rules. Zipwhip 2008 Stock Plan and 2018 Equity Incentive Plan In connection with its acquisition of Zipwhip, the Company assumed and replaced all stock options and restricted stock units of continuing employees issued under Zipwhip Amended and Restated 2008 Stock Plan and 2018 Equity Incentive Plan (“Zipwhip Plans”) that were unvested and outstanding on the acquisition date. The assumed equity awards will continue to be outstanding and will be governed by the provisions of the Zipwhip Plans. Under all plans, stock options generally expire 10 years from the date of grant and vest over periods determined by the board of directors. The vesting period for stock options and restricted stock units is generally four years from the date of grant. For existing employees and, effective February 2021, for new-hires the stock options and restricted stock units vest in equal monthly and quarterly installments, respectively, over the service period. 2016 Employee Stock Purchase Plan The Company’s Employee Stock Purchase Plan (“2016 ESPP”), as amended, initially became effective on June 21, 2016. A total of 2,400,000 shares of the Company’s Class A common stock were initially reserved for issuance under the 2016 ESPP. These available shares automatically increase each January 1, beginning on January 1, 2017, by the lesser of 1,800,000 shares of the Company's Class A common stock, 1 % of the number of shares of the Company’s Class A and Class B common stock outstanding on the immediately preceding December 31 or such lesser number of shares as determined by the Company’s compensation committee. On January 1, 2021 and 2020, the shares available for grant under the 2016 ESPP were automatically increased by 1,640,475 shares and 1,384,128 shares, respectively. The 2016 ESPP allows eligible employees to purchase shares of the Company’s Class A common stock at a discount of up to 15 % through payroll deductions of their eligible compensation, subject to any plan limitations. The 2016 ESPP provides for separate six-month offering periods beginning in May and November of each fiscal year. On each purchase date, eligible employees purchase the Company’s stock at a price per share equal to 85 % of the lesser of (i) the fair market value of the Company’s Class A common stock on the offering date or (ii) the fair market value of the Company’s Class A common stock on the purchase date. 110 Table of Contents As of December 31, 2021, total unrecognized compensation cost related to the 2016 ESPP was not significant. Stock-options and restricted stock units activity under the Company's 2008 Plan and 2016 Plan as well as respective Stock Incentive Plans of SendGrid and Segment was as follows: Stock Options Number of options outstanding Weighted- average exercise price (Per share) Weighted- average remaining contractual term (In years) Aggregate intrinsic value (In thousands) Outstanding options as of December 31, 2020 5,070,735 $ 51.71 6.85 $ 1,454,222 Granted 350,208 343.94 Assumed in acquisition 83,539 49.26 Exercised ( 1,733,819 ) 40.44 Forfeited and canceled ( 419,350 ) 131.01 Outstanding options as of December 31, 2021 3,351,313 $ 78.10 6.09 $ 646,760 Options vested and exercisable as of December 31, 2021 2,152,819 $ 37.21 4.92 $ 490,502 Year Ended December 31, 2021 2020 2019 (In thousands, except per share amounts) Aggregate intrinsic value of stock options exercised (1) $ 508,539 $ 603,597 $ 394,998 Total estimated grant date fair value of options vested $ 138,851 $ 107,854 $ 81,292 Weighted-average grant date fair value per share of options granted $ 216.29 $ 170.70 $ 58.13 ____________________________________ ( 1 ) Aggregate intrinsic value represents the difference between the fair value of the Company’s Class A common stock as reported on the New York Stock Exchange and the exercise price of outstanding “in-the-money” options. As of December 31, 2020, the Company had outstanding 555,000 shares of performance-based stock options with a weighted average exercise price of $ 31.72 and an aggregate intrinsic value of $ 170.3 million. All performance conditions had been met. During the year ended December 31, 2021, all of these stock options were exercised. The aggregate intrinsic value of these stock options exercised was $ 140.2 million. As of December 31, 2021, no performance-based stock options remain outstanding. As of December 31, 2021, total unrecognized compensation cost related to all unvested stock options was $ 151.5 million, which will be amortized on a ratable basis over a weighted-average period of 2.2 years. Restricted Stock Units Number of awards outstanding Weighted- average grant date fair value (Per share) Aggregate intrinsic value (In thousands) Unvested RSUs as of December 31, 2020 7,523,882 $ 131.76 $ 2,542,858 Granted 3,465,980 328.38 Vested ( 3,493,652 ) 114.70 Forfeited and canceled ( 1,020,510 ) $ 188.76 Unvested RSUs as of December 31, 2021 6,475,700 $ 237.22 $ 1,705,311 As of December 31, 2021, the Company had outstanding 24,697 restricted stock awards (“RSAs”) that were held in escrow with future vesting conditions. The aggregate intrinsic value of these awards was not significant. As of December 31, 2021, total unrecognized compensation cost related to unvested RSUs and RSAs was $ 1.4 billion, which will be amortized over a weighted-average period of 3.1 years. 111 Table of Contents As of December 31, 2021, the unrecognized compensation cost related to Class A common stock subject to future vesting conditions is $ 60.1 million, which will be amortized over a term of 2.0 years. Valuation Assumptions The fair value of employee stock options was estimated on the date of grant using the following assumptions in the Black-Scholes option pricing model: Year Ended December 31, Employee Stock Options: 2021 2020 2019 Fair value of common stock $ 268.55 - $ 409.21 $ 108.37 - $ 301.72 $ 103.70 - $ 130.70 Expected term (in years) 0.30 - 6.39 0.52 - 6.08 0.33 - 6.08 Expected volatility 42.9 % - 61.5 % 51.9 % - 65.1 % 49.0 % - 66.5 % Risk-free interest rate 0.1 % - 1.4 % 0.1 % - 1.4 % 1.6 % - 2.5 % Dividend rate — % — % — % Year Ended December 31, Employee Stock Purchase Plan: 2021 2020 2019 Expected term (in years) 0.50 0.50 0.49 - 0.50 Expected volatility 46.4 % - 58.7 % 54.4 % - 72.1 % 43.1 % - 50.3 % Risk-free interest rate — % - 0.1 % 0.1 % - 0.2 % 1.6 % - 2.4 % Dividend rate — % — % — % Stock-Based Compensation Expense The Company recorded total stock-based compensation expense as follows: Year Ended December 31, 2021 2020 2019 (In thousands) Cost of revenue $ 14,074 $ 8,857 $ 7,123 Research and development 258,672 173,303 126,012 Sales and marketing 213,351 103,450 60,886 General and administrative 146,188 76,301 70,297 Total $ 632,285 $ 361,911 $ 264,318 16. Net Loss Per Share Attributable to Common Stockholders The following table sets forth the calculation of basic and diluted net loss per share attributable to common stockholders during the periods presented: Year Ended December 31, 2021 2020 2019 Net loss attributable to common stockholders (in thousands) $ ( 949,900 ) $ ( 490,979 ) $ ( 307,063 ) Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted 174,180,465 146,708,663 130,083,046 Net loss per share attributable to common stockholders, basic and diluted $ ( 5.45 ) $ ( 3.35 ) $ ( 2.36 ) 112 Table of Contents The following outstanding shares of common stock equivalents were excluded from the calculation of the diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive: As of December 31, 2021 2020 2019 Stock options issued and outstanding 3,351,313 5,625,735 7,705,848 Restricted stock units issued and outstanding 6,475,700 7,523,882 8,490,517 Class A common stock reserved for Twilio.org 618,857 707,265 795,673 Class A common stock committed under ESPP 147,947 103,703 207,792 Convertible Notes (1) — 4,847,578 3,150,647 Class A common stock in escrow 75,506 75,612 — Class A common stock in escrow and restricted stock awards subject to future vesting 235,054 268,030 — Total 10,904,377 19,151,805 20,350,477 ____________________________________ (1) The Convertible Notes were fully redeemed in 2021 and were no longer outstanding as of December 31, 2021. As of December 31, 2020, the Company expected to settle the principal amount of the notes in shares of its Class A common stock, and as such used the if-converted method to calculate any potential dilutive effect of the debt settlement on diluted net income per share, if applicable. Prior to the fourth quarter 2020, the Company expected to settle the principal amount of these notes in cash and any excess in shares of the Company's Class A common stock. Hence, as of December 31, 2019, the Company used the treasury stock method to calculate any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. The conversion spread has a dilutive impact on diluted net income per share of Class A common stock when the average market price of the Company's Class A common stock for a given period exceeds the conversion price of $ 70.90 per share for the Convertible Notes. The conversion spread was calculated using the average market price of Class A common stock during the period, consistent with the treasury stock method. 17. Income Taxes The following table presents domestic and foreign components of loss before income taxes for the periods presented: Year Ended December 31, 2021 2020 2019 (In thousands) United States $ ( 737,360 ) $ ( 403,148 ) $ ( 328,902 ) International ( 223,569 ) ( 101,278 ) ( 33,314 ) Loss before provision for income taxes $ ( 960,929 ) $ ( 504,426 ) $ ( 362,216 ) Benefit for income taxes consists of the following: Year Ended December 31, 2021 2020 2019 Current: (In thousands) Federal $ 122 $ — $ — State 420 272 198 Foreign 8,274 5,215 2,684 Total 8,816 5,487 2,882 Deferred: Federal ( 13,772 ) ( 12,719 ) ( 49,393 ) State ( 4,083 ) ( 3,563 ) ( 7,474 ) Foreign ( 1,990 ) ( 2,652 ) ( 1,168 ) Total ( 19,845 ) ( 18,934 ) ( 58,035 ) Income tax benefit $ ( 11,029 ) $ ( 13,447 ) $ ( 55,153 ) 113 Table of Contents The following table presents a reconciliation of the statutory federal tax rate and the Company's effective tax rate: Year Ended December 31, 2021 2020 2019 Tax benefit at federal statutory rate 21 % 21 % 21 % State tax, net of federal benefit 8 12 8 Stock-based compensation 16 24 14 Credits 4 3 4 Foreign rate differential ( 1 ) ( 4 ) ( 2 ) Permanent book vs. tax differences — ( 1 ) — Change in valuation allowance ( 46 ) ( 51 ) ( 29 ) Other — — ( 1 ) Effective tax rate 2 % 4 % 15 % Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents the significant components of the Company's deferred tax assets and liabilities: As of December 31, 2021 2020 Deferred tax assets: (In thousands) Net operating loss carryforwards $ 1,054,585 $ 656,755 Accrued and prepaid expenses 24,831 15,408 Stock-based compensation 44,261 32,900 Research and development credits 148,282 92,899 Charitable contributions 15,219 8,229 Capped call — 4,475 Debt issuance cost — 230 Depreciable property 3,675 — Intangibles 135,500 135,500 Lease liability 71,651 68,566 Other 14,567 — Gross deferred tax assets 1,512,571 1,014,962 Valuation allowance ( 1,136,827 ) ( 677,782 ) Net deferred tax assets 375,744 337,180 Deferred tax liabilities: Capitalized software ( 28,825 ) ( 19,174 ) Prepaid expenses ( 1,649 ) ( 450 ) Acquired intangibles ( 251,034 ) ( 231,379 ) Property and equipment — ( 85 ) Convertible debt — ( 9,495 ) Right-of-use asset ( 64,277 ) ( 66,243 ) Deferred commissions ( 47,897 ) ( 21,162 ) Other — ( 2,876 ) Net deferred tax liability $ ( 17,938 ) $ ( 13,684 ) 114 Table of Contents The following table summarizes our tax carryforwards, carryovers, and credits: As of December 31, 2021 Expiration Date (If not utilized) (In thousands) Federal net operating loss carryforwards $ 320,167 Various dates beginning in 2029 Federal tax credits $ 132,920 Various dates beginning in 2029 Federal net operating loss carryforwards $ 3,906,263 Indefinite State net operating loss carryforwards $ 2,737,083 Various dates beginning in 2025 State tax credits $ 84,858 Indefinite Foreign net operating loss carryforwards $ 268,653 Indefinite A limitation may apply to the use of the net operating loss and credit carryforwards, under provisions of the Internal Revenue Code of 1986, as amended, and similar state tax provisions that are applicable if the Company experiences an “ownership change.” An ownership change may occur, for example, as a result of issuance of new equity. Should these limitations apply, the carryforwards would be subject to an annual limitation, resulting in a potential reduction in the gross deferred tax assets before considering the valuation allowance. The Company's accounting for deferred taxes involves the evaluation of a number of factors concerning the realizability of its net deferred tax assets. The Company primarily considered such factors as its history of operating losses, the nature of the Company's deferred tax assets, and the timing, likelihood and amount, if any, of future taxable income during the periods in which those temporary differences and carryforwards become deductible. Additionally, in December 2020, the Company completed an intra-entity asset transfer of certain intellectual property rights to an Irish subsidiary where its international business is headquartered. The transfer resulted in a step-up in the tax basis of the transferred intellectual property rights and a correlated $ 135.5 million increase in foreign deferred tax assets. At present, the Company does not believe that it is more likely than not that the federal, state and foreign net deferred tax assets will be realized, and accordingly, a full valuation allowance has been established. The valuation allowance increased by approximately $ 459.0 million and $ 421.9 million during the years ended December 31, 2021 and 2020, respectively. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: Year Ended December 31, 2021 2020 2019 (In thousands) Unrecognized tax benefit, beginning of year $ 191,183 $ 49,042 $ 15,635 Gross increases for tax positions of prior years 3,496 4,259 12,939 Gross decrease for tax positions of prior years ( 10,693 ) ( 931 ) ( 395 ) Gross increases for tax positions of current year 39,394 138,813 20,863 Unrecognized tax benefit, end of year $ 223,380 $ 191,183 $ 49,042 As of December 31, 2021, the Company had approximately $ 223.4 million of unrecognized tax benefits. If the $ 223.4 million is recognized, $ 6.6 million would affect the effective tax rate. The remaining amount would be offset by the reversal of related deferred tax assets which are subject to a full valuation allowance. The Company recognizes interest and penalties, if any, related to uncertain tax positions in its income tax provision. As of December 31, 2021 and 2020, such amounts are not significant. The Company does not anticipate any significant changes within 12 months of December 31, 2021, in its uncertain tax positions that would be material to the consolidated financial statements taken as a whole because nearly all of the unrecognized tax benefit has been offset by a deferred tax asset, which has been reduced by a valuation allowance. 115 Table of Contents The Company files U.S. federal income tax returns as well as income tax returns in many U.S. states and foreign jurisdictions. As of December 31, 2021, the tax years 2008 through the current period remain open to examination by the major jurisdictions in which the Company is subject to tax. Fiscal years outside the normal statute of limitation remain open to audit by tax authorities due to tax attributes generated in those early years, which have been carried forward and may be audited in subsequent years when utilized. The Company is fully reserved for all open U.S. federal, state and local, or non-U.S. income tax examinations by any tax authorities. On June 7, 2019, a three-judge panel from the U.S. Court of Appeals for the Ninth Circuit overturned the U.S. Tax Court's decision in Altera Corp. v. Commissioner and upheld the portion of the Treasury regulations under Section 482 of the Internal Revenue Code that requires related parties in a cost-sharing arrangement to share expenses related to share-based compensation. As a result of this decision, the Company's gross unrecognized tax benefits increased to reflect the impact of including share-based compensation in cost-sharing arrangements. On July 22, 2019, Altera filed a petition for a rehearing before the full Ninth Circuit and the request was denied on November 12, 2019. On February 10, 2020, Altera filed a petition to appeal the decision to the Supreme Court and on June 22, 2020 the Supreme Court denied the petition. There is no impact on the Company’s effective tax rate for years ended December 31, 2021 and 2020 due to a full valuation allowance against its deferred tax assets. We will continue to monitor future developments and their potential effects on our consolidated financial statements. In connection with the Zipwhip acquisition, the Company recorded a net deferred tax liability which provides an additional source of taxable income to support the realization of the pre-existing deferred tax assets and, accordingly, during the year ended December 31, 2021, the Company released a total of $ 15.9 million of its U.S. valuation allowance. The Company continues to maintain a valuation allowance for its U.S. Federal and State net deferred tax assets. In connection with the Segment acquisition, the Company recorded a net deferred tax liability which provides an additional source of taxable income to support the realization of the pre-existing deferred tax assets and, accordingly, during the year ended December 31, 2020, the Company released a total of $ 13.8 million of its U.S. valuation allowance. The Company continues to maintain a valuation allowance for its U.S. Federal and State net deferred tax assets. In connection with the SendGrid acquisition, the Company recorded a net deferred tax liability which provides an additional source of taxable income to support the realization of the pre-existing deferred tax assets and, accordingly, during the year ended December 31, 2019, the Company released a total of $ 55.0 million of its U.S. valuation allowance. The Company continues to maintain a valuation allowance for its U.S. Federal and State net deferred tax assets. The provision for income taxes recorded in the years ended December 31, 2021 and 2020, consists primarily of income taxes, withholding taxes in foreign jurisdictions in which the Company conducts business and the tax benefit related to the release of valuation allowance from acquisitions. The Company’s U.S. operations have been in a loss position and the Company maintains a full valuation allowance against its U.S. deferred tax assets. 18. Subsequent Events As described in Note 13(a), the Company was a party to a certain Framework Agreement, as amended, and a Subscription Agreement pursuant to which the Company intended to purchase up to $ 750.0 million in common stock of MBAC, subject to certain terms and conditions. In February 2022, Syniverse, MBAC and the Merger Sub mutually terminated the Merger Agreement and the related proposed Merger. The parties agreed to this termination because t he rate of MBAC shareholder redemptions for the proposed transaction would have exceeded the minimum cash condition for closing, which occurred as a result of the recent changes in market conditions. Consequently, the Company will not be purchasing any shares of common stock of, or making any investments in, MBAC. Notwithstanding the above, the Framework Agreement between the Company, Syniverse and Carlyle remains in full force and effect. Pursuant to the terms and subject to the closing conditions set forth in the Framework Agreement, the parties are pursuing the alternative transaction, whereby the Company will make a minority investment of $ 500.0 million to $ 750.0 million in Syniverse and the parties (or their applicable subsidiaries) will enter into a wholesale agreement. The transaction is expected to close in 2022. 116 Table of Contents Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure None.