Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Basis of Presentation The consolidated financial statements and accompanying notes were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Principles of Consolidation The consolidated financial statements include the accounts of Bandwidth Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires the Company to make estimates and judgments that affect the amounts reported in these financial statements and accompanying notes. These estimates in the consolidated financial statements include, but are not limited to, allowance for doubtful accounts, reserve for expected credit losses, reserve for sales credits, recoverability of long lived and intangible assets, fair value of acquired intangible assets and goodwill, discount rates used in the valuation of right-of-use assets and lease liabilities, the fair value of the liability components of the Company’s Convertible Notes (as defined herein), estimated period of benefit, valuation allowances on deferred tax assets, certain accrued expenses and contingencies, economic and demographic actuarial assumptions related to pension and other postretirement benefit costs and liabilities. Although the Company believes that the estimates it uses are reasonable, due to the inherent uncertainty involved in making these estimates, actual results reported in future periods could differ from those estimates. Revenue Recognition Revenue recognition commences upon transfer of control of promised goods or services to customers in an amount that the Company expects to receive in exchange for those products or services. 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. Infrequently, Bandwidth’s contracts with customers may include multiple performance obligations. For such arrangements, revenues are allocated to each performance obligation based on its relative standalone selling price. Generally, standalone selling prices are determined based on the prices charged to similar customers for similar services. When required as part of providing service, revenues and associated expenses related to nonrefundable, upfront service activation and setup fees are deferred and recognized over the longer of the associated service contract period or estimated customer life. The Company’s contracts do not contain general rights of return. However, occasionally credits may be issued. The Company’s 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. The Company maintains a reserve for sales credits. Credits are accounted for as variable consideration and are estimated based on several inputs including historical experience and current trends of credit issuances. Adjustments to the reserve are recorded against revenue. The Company has various sales commission plans for which eligible employees can earn commissions from the sale of products and services to customers. Eligible employees must be employed at the time of payment in order to receive a commission. The Company pays commissions over time and a corresponding requisite substantive service condition exists for the employee to receive the commission. The Company determined that the timing of the commission payments and the underlying service performed by the employee were commensurate. Accordingly, sales commissions are generally expensed as incurred. These costs are recorded within sales and marketing expenses. Nature of Products and Services Revenue consists primarily of two categories: (1) cloud communications and (2) messaging surcharges, which are described and quantified below. Year ended December 31, 2024 2023 2022 (In thousands) Cloud communications $ 539,753 $ 478,892 $ 474,576 Messaging surcharges 208,734 122,225 98,576 Total revenue $ 748,487 $ 601,117 $ 573,152 Cloud Communications Cloud communications revenue consists of the sale of communications services offered through Application Programming Interface (“API”) software solutions to customers and is derived from (i) reoccurring sources such as per minute voice usage and voice calling, per text message usage and other usage services and fees, and (ii) monthly recurring charges arising from phone number services, 911-enabled phone number services, messaging services and other services. The majority of the Company’s cloud communications revenue is generated from reoccurring fees earned from customers accessing and using the Company’s communications platform. Access to the Company’s communications platform is considered a series of distinct services with continuous transfer of control to the customer, comprising one performance obligation. Reoccurring fees are recognized in revenue in the period the traffic traverses the Company’s network. For the years ended December 31, 2024, 2023 and 2022, revenue from reoccurring cloud communications fees represented $401.4 million, $346.9 million, and $354.0 million of total revenue, respectively. Revenue from recurring fees is recognized on a ratable basis as the service is provided, which is typically one month. For the years ended December 31, 2024, 2023 and 2022, revenue from recurring cloud communications fees represented $138.4 million, $132.0 million and $120.6 million of total revenue, respectively. Messaging surcharges Messaging surcharge revenue consists of pass-through messaging surcharges imposed by the major mobile carriers in North America and is recognized in revenue during the period in which the messaging traffic traverses the Company’s network. Contract Assets and Liabilities The following table provides information about receivables and contract liabilities from contracts with customers: As of December 31, 2024 2023 (In thousands) Receivables (1) $ 86,455 $ 78,155 Contract liabilities (2) 14,986 16,465 ________________________ (1) Included in accounts receivable, net of allowance for doubtful accounts on the consolidated balance sheets. (2) Included in current portion of deferred revenue and deferred revenue, net of current portion on the consolidated balance sheets. Deferred revenue is recorded when cash payments are received in advance of future usage on contracts. Revenue is typically recognized in the following month when service is rendered or, in the case of nonrefundable upfront fees, over the estimated period of benefit from the date the fee is incurred by the customer. Customer refundable payments are recorded as advanced billings. During the year ended December 31, 2024, the Company recognized revenue of $6.6 million related to contract liabilities recorded at the beginning of the year. The Company expects to recognize $7.0 million in revenue over the next 12 months related to its contract liabilities as of December 31, 2024. Cost of Revenue Cost of revenue consists of fees paid to other network service providers, network operations costs, personnel costs, allocated costs of facilities and information technology, amortization of acquired technology intangibles and depreciation. Fees paid to other network service providers arise when the Company purchases services such as minutes of use, phone numbers, messages, porting of customer numbers and network circuits. Network operations costs are incurred for web services and cloud infrastructure, capacity planning and management, software licenses, hardware and software maintenance fees, customer support and network-related facility rents. Personnel costs (including non-cash stock-based compensation expenses) arise for employees who are responsible for the delivery of services, and operations and maintenance of, the communications network. Operating Expenses Research and Development Research and development expenses consist of salaries and related personnel costs for the design, development, testing and enhancement of our cloud network and software products. Research and development expenses include depreciation and allocated costs for facilities and information technology utilized by our research and development staff. Sales and Marketing Sales and marketing expenses consist of salaries and related personnel costs, commissions, and costs related to advertising, marketing, brand awareness activities, sales support and professional services fees, and customer billing and collections functions. Sales and marketing expenses include depreciation, amortization of acquired customer relationship intangible assets, and allocated costs of facilities and information technology utilized by our sales and marketing staff. General and Administrative General and administrative expenses consist of salaries and related personnel costs for accounting, legal, human resources, corporate, and other administrative and compliance functions. General and administrative expenses include depreciation, expenditures for third party professional services, and allocated costs of facilities and information technology utilized by our corporate and administrative staff. Cash and Cash Equivalents The Company classifies all highly liquid investments with original stated maturities of three months or less from the date of purchase as cash equivalents. All highly liquid investments with original stated maturities of greater than three months from the date of purchase are classified as current marketable securities. Cash deposits are primarily in financial institutions in the United States. However, cash for monthly operating costs of international operations are deposited in banks outside the United States. The Company has a policy of making investments only with commercial institutions that have at least an investment grade credit rating. The Company utilizes money market funds as an investment option and only invests in AAA rated funds. Marketable Securities The Company’s marketable securities consist of time deposits and commercial paper. The Company classifies marketable securities as available-for-sale at the time of purchase and reevaluates such classification as of each balance sheet date. The Company may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, the Company classifies investments with maturities greater than 90 days as marketable securities in the accompanying consolidated balance sheets. Available-for-sale securities are recorded at their estimated fair value at the end of each reporting period. Unrealized gains and losses are excluded from earnings and recorded as a separate component within accumulated other comprehensive loss on the consolidated balance sheets until realized. Interest income is reported within other income, net on the consolidated statements of operations. The Company evaluates its investments to assess whether the amortized cost basis is in excess of estimated fair value and determines what amount of that difference, if any, is caused by expected credit losses. Allowance for credit losses are recognized as a charge in other income, net on the consolidated statements of operations, and any remaining unrealized losses are included in accumulated other comprehensive loss on the consolidated balance sheets. Due to the nature and investment grade of the Company’s marketable securities, there were no credit losses recorded for the year ended December 31, 2024. There have been no impairment charges for any unrealized losses during the period. The Company determines realized gains and losses on the sale of marketable securities using the specific identification method and records such gains and losses in other income, net on the consolidated statements of operations. Accounts Receivable and Current Expected Credit Losses Accounts receivable are stated at realizable value, net of allowances, which includes an allowance for doubtful accounts and a reserve for expected credit losses. The allowance for doubtful accounts is based on management’s assessment of the collectability of its customer accounts. The Company regularly reviews the composition of the accounts receivable aging, historical bad debts, changes in payment patterns, customer creditworthiness, current economic trends, and reasonable and supportable forecasts about the future. Relevant risk characteristics include customer size and historical loss patterns. Management has evaluated the expected credit losses related to trade accounts receivable and determined that allowances of approximately $2.2 million and $1.1 million for uncollectible accounts and customer balances that are disputed were required as of December 31, 2024 and 2023, respectively. Refer to Note 4, “Financial Statement Components” to these consolidated financial statements, for a rollforward of the components of the allowances for the years ended December 31, 2024, 2023 and 2022. The Company includes unbilled receivables in its accounts receivable balance. Generally, these receivables represent earned revenue from services provided to customers, which will be billed in the next billing cycle. All amounts are considered collectible and billable. As of December 31, 2024 and 2023, unbilled receivables were $46.8 million and $43.6 million, respectively. Concentration of Credit Risk Financial instruments that are exposed to concentration of credit risk consist primarily of cash and cash equivalents, marketable securities and trade accounts receivable. The Company maintains its cash, cash equivalents and marketable securities with high credit-quality financial institutions. Certain balances held by such financial institutions exceed federally-insured limits. With regard to customers, credit evaluation and account monitoring procedures are used to minimize the risk of loss. The Company believes that no additional credit risk beyond amounts provided for by the allowance for doubtful accounts are inherent in accounts receivable. As of December 31, 2024 and 2023, no individual customer represented more than 10% of the Company’s accounts receivable, net of allowance for doubtful accounts. For the years ended December 31, 2024, 2023 and 2022, no individual customer represented more than 10% of the Company’s revenue. Leases The Company determines if an arrangement is or contains a lease at inception and reassesses that conclusion if the contract is modified. All leases are assessed for classification as an operating lease or a finance lease. For facility leases, the Company does not account for lease and non-lease components as a single lease component. Operating lease 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. ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company does not include options to extend or terminate the lease unless it is reasonably certain that it will exercise any such options. Variable lease payments, such as common areas maintenance costs, are not included in the measurement of ROU assets and lease liabilities, and instead are expensed as incurred. The Company generally uses its incremental borrowing rate (“IBR”) based on the information available at commencement to determine the present value of lease payments, except when an implicit interest rate is readily determinable. Operating lease expense attributable to lease payments is recognized on a straight-line basis over the lease term and is part of allocated facilities costs based on employee headcount within the cost of revenue, research and development, sales and marketing, and general and administrative expense categories on the Company’s consolidated statements of operations. The Company presents the operating leases in long-term assets and current and long-term liabilities in the accompanying consolidated balance sheets. Finance leases result in the recognition of depreciation expense, which is recognized on a straight-line basis over the expected life of the leased asset, and interest expense, which is recognized following an effective interest rate method. Depreciation expense attributable to finance leases is included in operating expenses on the Company’s consolidated statements of operations. Finance leases are reported in property, plant and equipment, net, accrued expenses and other current liabilities, and other liabilities on the Company’s consolidated balance sheets. The Company did not have significant finance leases as of December 31, 2024 and 2023. The Company does not recognize ROU assets or lease liabilities for leases with a term of twelve months or less. Lease cost for short-term leases is recognized on a straight-line basis over the lease term. Property, Plant and Equipment, net Property, plant and equipment, net is stated at cost, less accumulated depreciation and amortization. Depreciation and amortization is calculated on a straight-line basis over the estimated useful lives of those assets. Refer to Note 6, “Property, Plant and Equipment” to these consolidated financial statements, for the useful lives of the Company’s property, plant and equipment as of December 31, 2024 and 2023. Deferred Costs The Company defers certain direct and incremental upfront costs related to the generation of a revenue stream or obtaining a new customer agreement. These costs include installment fees, activation and other telecommunication fees. The Company capitalizes these costs and amortizes them over the longer of the term of the customer contract or the estimated period of benefit, which is approximately four years. Internal-Use Software Development Costs Internal-use software includes software that has been acquired, internally developed, or modified exclusively to meet the Company’s needs. 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 the expenditures will result in additional functionality, and expenses costs incurred for maintenance and minor upgrades and enhancements. Costs related to preliminary project activities and post-implementation operating activities are expensed as incurred. Capitalized costs of platform and other software applications are included in property, plant and equipment, net. These assets are placed into service when ready for use and amortized over the estimated useful life of the software on a straight-line basis over four 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. Debt Issuance Costs The Company incurs debt issuance costs associated with obtaining and entering into credit agreements and issuing convertible notes. These costs customarily include non-refundable structuring fees, commitment fees, up-front fees and syndication expenses. The Company has a policy of deferring and amortizing these costs based on the effective interest method over the term of the credit agreements or the convertible notes, as applicable. Amortization of Intangibles 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 historical cost and reviewed for impairment at least annually. The useful lives of the Company’s intangible assets as of December 31, 2024 and 2023 are as follows: Customer relationships 15 - 20 years Developed technology 10 years Other, definite lived 2 - 7 years Licenses, indefinite lived Indefinite Goodwill In accordance with Accounting Standards Codification 350, “Intangibles - Goodwill and Other” (“ASC 350”), goodwill is not amortized, but rather is reviewed for impairment at the reporting unit level on the last day of the Company’s fourth quarter of each fiscal year, or when there is evidence that events or changes in circumstances indicate that the fair value of the reporting unit is less than the carrying amount of the reporting unit, including goodwill. The Company establishes its reporting units based on its current organizational structure and management’s view of the business. The Company has determined it has one reporting unit. Under ASC 350, the Company has the option to first assess qualitatively whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. In performing qualitative assessments, consistent with ASC 350-20-35-3C, the Company considers, among other factors, macroeconomic conditions (both in the United States and internationally), the Company’s overall financial performance (including, but not limited to, comparisons to prior periods, current period internal expectations, and comparable peer companies), broader industry and market considerations, and the trading price performance of the Company’s Class A common stock. As of December 31, 2024, the Company completed a qualitative assessment under ASC 350 to determine whether the existence of events or circumstances indicated that it was more likely than not that the fair value of its reporting unit was less than its respective carrying value. The Company concluded that based on the relevant events and circumstances, it was more likely than not that the reporting unit’s fair value exceeded its related carrying value and therefore no quantitative assessment was required. No goodwill impairment charges were recorded for the years ended December 31, 2024, 2023 and 2022. Impairment of Long-Lived Assets The Company evaluates long-lived assets, including property, plant and equipment, operating right-of-use assets and definite lived 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. Business Combinations The Company uses the acquisition method of accounting for business combinations which requires the tangible and intangible assets acquired and liabilities assumed to be recorded at their respective fair market value as of the acquisition date. Goodwill represents the excess of the consideration transferred over the fair value of the net assets acquired. The fair values of the assets acquired and liabilities assumed are determined based upon the Company’s valuation and involves making significant estimates and assumptions based on facts and circumstances that existed as of the acquisition date. The Company uses a measurement period following the acquisition date to gather information that existed as of the acquisition date that is needed to determine the fair value of the assets acquired and liabilities assumed. The measurement period ends once all information is obtained, but no later than one year from the acquisition date. Advertising Costs The Company expenses advertising costs as incurred. Advertising costs totaled $1.2 million, $1.2 million and $1.5 million for the years ended December 31, 2024, 2023 and 2022, respectively, which are included in sales and marketing expenses in the accompanying consolidated statements of operations. Commissions Commissions consist of variable compensation earned by sales personnel and third-party resellers. Sales commissions associated with the acquisition of a new customer contract are paid over time, based on monthly revenues, and are recognized as sales and marketing expense in the period incurred. Stock-Based Compensation The Company accounts for stock-based compensation expense related to all stock-based awards based on the fair value of the award on the grant date. Stock-based compensation expense is recognized on a straight-line basis over the requisite service period, which is generally three The Company has elected to estimate expected forfeitures, and, as such, the Company must also determine a forfeiture rate to calculate the stock-based compensation expense for awards. Through December 31, 2024, the Company recognized compensation expense for only the portion of restricted stock units expected to vest using an estimated forfeiture rate that was derived from historical employee termination behavior. As of December 31, 2024, all outstanding stock options are fully vested. Income Taxes The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on temporary differences between the financial statement and tax basis of assets and liabilities using enacted tax rates. The Company recognizes the effect of a change in tax rates on deferred tax assets and liabilities in the period that includes the enactment date. The Company reduces the measurement of a deferred tax asset, if necessary, by a valuation allowance if it is more likely than not that it will not realize some or all the deferred tax asset. Quarterly, the Company reviews the deferred tax assets for recoverability based on historical taxable income, projected future taxable income, the expected timing of the reversals of existing temporary differences and the implementation of prudent and feasible tax planning strategies. The evaluation of the recoverability of deferred tax assets requires judgment in assessing future profitability. Should there be a change in the ability to recover deferred tax assets, the Company’s income tax provision would increase or decrease in the period in which the assessment is changed. The Company accounts for uncertain tax positions by recognizing the financial statement effects of a tax position only when, based upon technical merits, it is more likely than not that the position will be sustained upon examination. The tax benefit recognized is measured as the largest amount of benefit determined on a cumulative probability basis that the Company believes is more likely than not to be realized upon ultimate settlement of the position. The Company recognizes potential accrued interest and penalties associated with unrecognized tax positions in income tax benefit in the accompanying consolidated statements of operations. Basic and Diluted (Loss) Income per Common Share Basic net (loss) income per share attributable to common stockholders is calculated by dividing the net (loss) income by the weighted-average number of shares of common stock outstanding for the period. Diluted net (loss) income per share is calculated by giving effect to all potentially dilutive shares of common stock, including stock options, and stock related to unvested restricted stock awards and convertible debt. In periods of net loss, all potentially issuable shares of common stock are excluded from the diluted net loss per share computation because they are anti-dilutive. The Company is in a net loss position for the years ended December 31, 2024 and 2023, and therefore diluted shares equals basic shares. Foreign currency translation The Company has foreign operations with non-USD functional currencies. The Euro and British Pound are the primary functional currencies for the Company’s international operations. All of the assets and liabilities of these subsidiaries are translated to U.S. dollars at the exchange rate in effect at the balance sheet date, and equity accounts are translated at historical exchange rates. Revenue and expenses are translated at average exchange rates in effect during each reporting period . The net effect of currency translation adjustments is included in shareholder’s equity as a component of accumulated other comprehensive loss in the accompanying consolidated balance sheets. Foreign currency transaction gains and losses are realized upon cash settlement of transactions denominated in currencies others than the functional currency. They result from exchange rate changes during the period of time between the consummation and cash settlement of such transactions. When realized, foreign currency transaction gains and losses are recognized in current period earnings as incurred, and included in other income, net in the Company’s consolidated statements of operations. Foreign exchange gains and losses, which result from the process of remeasuring foreign currency assets and liabilities into the appropriate functional currency at exchange rates in place as of the reporting date, are included in other income, net in the Company’s consolidated statements of operations. Fair Value of Financial Instruments The Company minimizes its credit risk associated with investments by investing primarily in investment grade, liquid securities. The Company policy is designed to preserve capital, maintain liquidity and minimize credit risk, and the policy limits exposure to any one issuer and also establishes minimum credit ratings of approved investments. Periodic evaluations of relative credit standing of those issuers are considered in the Company's investment strategy. The Company uses a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis, as well as assets and liabilities measured at fair value on a non-recurring basis, in periods subsequent to their initial measurement. The hierarchy requires use of observable inputs when available, and to minimize the use of unobservable inputs when determining fair value. The three tiers are defined as follows: • Level 1. Observable inputs based on unadjusted quoted prices in active markets for identical assets or liabilities; • Level 2. Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and • Level 3. Unobservable inputs for which there is little or no market data, which requires the Company to develop its own assumptions. 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. Comprehensive Loss The Company has elected to present comprehensive loss and its components as a separate financial statement. Comprehensive loss refers to net (loss) income 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 income. Business Interruption Insurance Recovery Beginning in September 2021, the Company’s communications network was subjected to a distributed denial of service attack (the “DDoS Attack”) that caused intermittent communi |