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•	our ability to attract and retain customers, including large enterprises;

•	our approach to identifying, attracting and keeping new and existing customers, as well as our expectations regarding customer turnover;

•	our beliefs regarding network traffic growth and other trends related to the usage of our products and services;

•	our expectations regarding revenue, costs, expenses, gross margin, dollar based net retention rate, Adjusted EBITDA and capital expenditures;

•	our beliefs regarding the growth of our business and how that impacts our liquidity and capital resources requirements;

•	the sufficiency of our cash and cash equivalents to meet our liquidity needs;

•	our ability to attract, train, and retain qualified employees and key personnel;

•	our beliefs regarding the expense and productivity of and competition for our sales force;

•	our expectations regarding headcount;

•	our ability to maintain and benefit from our corporate culture;

•	our plans to further invest in and grow our business, and our ability to effectively manage our growth and associated investments;

•	our ability to introduce new products and services and enhance existing products and services;

•	our ability to compete successfully against current and future competitors;

•	the evolution of technology affecting our products, services and markets;

•	the impact of certain new accounting standards and guidance as well as the time and cost of continued compliance with existing rules and standards;

•	our beliefs regarding the use of non-GAAP financial measures;

•	our ability to maintain, protect and enhance our intellectual property;

•	our expectations regarding litigation and other pending or potential disputes;

•	our ability to comply with modified or new laws and regulations; and

•	the increased expenses associated with being a public company.

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•	Enabling local and toll-free numbers via software API: Our platform empowers enterprises with a capability to activate and manage phone numbers instantly and at scale. Using our easy to use software APIs, our enterprise customers can easily add additional lines to their business as well as for their end users.

•	Automating voice communication while preserving privacy: Our software APIs enable voice communication capabilities from a mobile application to an individual or a group with or without disclosing personal identity.

•	Embedding ‘click-to-call’ communication feature: We enhance our enterprise customers mobile and web marketing capabilities by embedding click-to-call functionality in their customer outreach, including advertising campaigns that enables them to connect with consumers instantly.

•	Real-time call analytics: We provide our enterprise customers with real-time call analytics through our dashboard that correlates the raw data from calls with CRM records, including the call duration, customer sentiment and other attributes, in order to provide meaningful contextual sales and other business insights.

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Automated real-time notification and alerts: Our software APIs empower our enterprise customers with predefined functionalities to send and receive text messages to and from an application to an individual or a group. Our customers often build more customized use cases on top of our predefined use cases. For instance, ZipRecruiter uses this functionality to update job seekers of available jobs in real time via automated text alerts.

•	Two-factor authentication: We enable enterprises to verify the identity and maintain security of end users through our software-based SMS verification service that sends unique codes to end users in order to log in to mobile and web applications.

•	Group messaging: Enterprises utilize our platform to collaborate with their end users on a real-time basis by enabling group messaging within their user community to share messages, videos, carry out polls and surveys amongst other uses without leaving the application.

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Easy to Build and Deploy. Our easy-to-use, intuitive software APIs are ready to launch and scale from day one. We enable enterprises to rapidly and easily scale communications functionalities to a vast range of applications and devices. Our technology requires minimal lines of code to build customized applications, which allows for rapid composition of customized solutions and seamless embedding within other applications.

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Easy to Scale. We enable enterprises to easily scale nationwide at launch, without sacrificing quality, while meeting the most stringent requirements. We can deliver full end-to-end automation for even the largest of enterprises using our IP voice network, which is the largest of any CPaaS provider based on the number of rate centers, a measure for the footprint covered by our IP voice network. We are able to support high user volumes without impacting deliverability. Our software, built on our own IP voice network, removes complexity, eliminates performance degradation and increases cost efficiencies at scale.

•	Flexibility. Our software APIs are easy to deploy and use and allow for the creation of solutions to address a broad array of use cases. Our software can be implemented directly into product workflow for a variety of custom solutions such as creation of virtual call centers, group messaging and dynamic call location routing. We enable developers to easily and rapidly innovate with our platform.

•	Enhanced Quality and Reliability. We offer greater levels of quality and delivery assurance than providers offering services across the public Internet or through partnerships. As a result, the enterprises we serve have enjoyed 99.9% network uptime in 2017 and we have not experienced any material system failures in the past three years.

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Total Accountability. The ability to vertically integrate our software platform with our own IP voice network provides us with a differentiated ability to continuously monitor, report and resolve any software- or network-related issues on a real-time basis. For our enterprise customers, having a single platform solution for their entire communications requirements, including software and network, provides tremendous value with respect to time and financial resources. Our service-level agreements with our enterprise customers assures that we provide high quality service and gives them peace of mind and confidence in our service.

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Lower Total Cost to Our Customers. The differentiated pairing of our software combined with owning the delivery capability through our IP voice network leads to significant savings for the enterprises we serve as compared to our competitors. Our IP voice network lowers total cost to our customers as compared to our competitors because of our reduced capital expenditure requirements and lower marginal costs at scale, which we are able to pass on to our customers.

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Highly Scalable Platform Built for the Enterprise. We built our Bandwidth Communications Platform from the ground up as an enterprise-grade cloud application. As a result, our deployment is fast, our software APIs are flexible and easy-to-use, and we enable enterprises to launch and scale on day one. Our software APIs allow the enterprise customers we serve to grow with flexibility and seamlessly embed communications in their applications or devices. Our scalable platform allows us to serve large-scale Internet companies and cloud service providers.

•	Broadest, Most Complete Solutions in the Industry. We provide enterprises the broadest, most complete communications services solutions in the industry through our integrated software and IP voice network. Our large library of voice and text APIs enables our customers to incorporate into their products and services a broad range of capabilities not otherwise attainable.

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Purpose-Built IP Voice Network. Our Bandwidth Communications Platform’s IP voice network, which we own and operate nationwide, supports our ability to scale at a reliable and consistent quality for the enterprises we serve. The control and scale we have over our own IP voice network integrated with our Bandwidth Communications Platform provides us distinct competitive advantages that include consistent high quality, in-depth enterprise support, real-time network visibility and economies of scale.

•	Deep Experience and Expertise in Voice and Messaging. The combination of our versatile software API platform and our IP voice network control allows us to offer not just best efforts, but best-in-class voice and messaging solutions for enterprises. Our senior leadership team has a combined 135 years of industry experience and an average tenure with Bandwidth of 10 years.

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Growing, Long-Term Relationships with Low Customer Churn. We deliver comprehensive solutions that address the unique and complex needs of the enterprises we serve. As a result, these enterprises have continued to innovate and grow with our platform over extended timeframes. Our relationship with each of the enterprises we serve often expands across different product suites, divisions and use cases over time. Our customers include large enterprises and small and medium-sized businesses across various industries, and we rarely lose customers that have been on our platform for more than three months. For example, our largest enterprise customer has been on our platform for more than ten years. Based on surveys conducted after customer interactions in 2017, our customers have expressed a 97% satisfaction rate.

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CPaaS-Based 911 Network Capabilities. We believe we are the only CPaaS software provider with 911 capabilities. We believe our 911 capabilities provide a significant advantage as compared to software platform providers that are enabling residential voice services through new connected device experiences. Moreover, our dynamic geospatial routing capability routes 911 calls based on a real-time location of the caller to produce industry-leading results.

•	Expand Existing Enterprise Relationships. We will continue to expand our relationships with our existing enterprise customers. For example, enterprises often initially purchase only our voice solution and later expand to also purchase our messaging and 911 services. Additionally, we are able to help enterprises scale efficiently and offer their solutions to more of their customers as they grow.

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•	Grow Our Enterprise Customer Base. We believe there is a substantial opportunity to increase our enterprise customer base across a broad range of industries and companies. We plan to continue to grow and invest in our direct sales force and marketing to increase our enterprise customer base.

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Continue to Innovate Our Platform. We are committed to building on our track record of leveraging our innovative product capabilities to meet our customers’ needs, just as we have done throughout our history, through dramatic waves of change in communications technology. We were early to deploy software-based networks and to offer hosted cloud-based voice services, while building out one of the fastest growing IP voice networks over the last ten years. Our team has continued to adapt to a dynamic environment to grow our business, and we intend to invest in continued development of our platform and product features to support new use cases such as virtual personal assistants ("VPAs") and help our enterprise customers succeed as communications technologies evolve.

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Continue Our Focus on Enterprise Customer Satisfaction. We intend to continue focusing on delivering world-class services and support to the enterprises we serve to ensure a high level of satisfaction. We believe that satisfied customers provide vital product feedback, purchase additional services, renew contracts at a high rate and provide broad advocacy and new customer referrals for our business.

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Explore the Development and Growth of Our International Offerings. Today, our international services are limited to outbound international calling and outbound international messaging. Some of our enterprise customers operate globally or have plans to so. While we do not have specific expansion plans, we are actively exploring opportunities, including those where we might have a cost or quality advantage in serving our customers.

•	Pursue Acquisitions and Strategic Investments Selectively. We may selectively pursue acquisitions and strategic investments in businesses and technologies that strengthen our platform.

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•	platform scalability, reliability and performance;

•	network control and quality;

•	completeness of offering;

•	ease of integration and programmability;

•	product features;

•	customer support;

•	ability to deliver measurable value and savings;

•	the cost of deploying and using our service offerings;

•	the strength of sales and marketing efforts;

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•	brand awareness and reputation; and

•	credibility with product executives and developers.

•	CPaaS companies that offer a narrower set of software APIs, less robust customer support and fewer other features while relying on third-party networks and physical infrastructure; and

•	network service providers that offer limited developer functionality on top of their own networks and physical infrastructure, such as AT&T, Level 3 and Verizon.

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•	our annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and all amendments to those reports as soon as reasonably practicable after such material is electronically filed with or furnished to the Securities and Exchange Commission;

•	our policies related to corporate governance, including our Code of Business Conduct and Ethics applying to our directors, officers and employees (including our principal executive officer and principal financial and accounting officer) that we have adopted to meet applicable rules and regulations;

•	the charters of the Audit and Compensation Committees of our Board of Directors.

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•	the availability and retention of qualified and effective personnel with the expertise required to sell and operate effectively or successfully;

•	the overall economic health of new and existing markets;

•	the number and effectiveness of competitors;

•	the pricing structure under which we will be able to purchase services required to serve our customers;

•	the availability to us of technologies needed to remain competitive; and

•	federal and state and regulatory conditions, including the maintenance of state regulation that protects us from unfair business practices by traditional network service providers or others with greater market power who have relationships with us as both competitors and suppliers.

•	CPaaS companies that offer a narrower set of software APIs, less robust customer support and fewer other features while relying on third-party networks and physical infrastructure; and

•	network service providers that offer limited developer functionality on top of their own networks and physical infrastructure, such as AT&T, Level 3 and Verizon.

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•	we do not maintain or improve our current relationships with existing key customers;

•	we are not able to expand the available capacity on our network to meet our customers’ demands in a timely manner;

•	we do not develop new large wholesale and enterprise customers; or

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•	our customers determine to obtain these services from either their own network or from one of our competitors,

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•	quoting, accepting and inputting customer orders for services;

•	provisioning, installing and delivering services;

•	providing customers with direct access to the information systems included in our Bandwidth Communications Platform so that they can manage the services they purchase from us, generally through web-based customer portals; and

•	billing for services.

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•	Our 911 calling services are different, in significant respects, from the 911 service associated with traditional wireline and wireless telephone providers and, in certain cases, with other VoIP providers.

•	In the event of a power loss or Internet access interruption experienced by a customer, our service may be interrupted.

•	Our customers’ end users may experience lower call quality than they are used to from traditional wireline or wireless telephone companies, including static, echoes and delays in transmissions.

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•	Our customers’ end users may not be able to call premium-rate telephone numbers such as 1-900 numbers and 976 numbers.

•	service interruptions;

•	misfunction of our Bandwidth Communications Platform on which our enterprise users rely for voice, messaging or 911 functionality;

•	exposure to customer liability;

•	the inability to install new service;

•	the unavailability of employees necessary to provide services;

•	the delay in the completion of other corporate functions such as issuing bills and the preparation of financial statements; or

•	the need for expensive modifications to our systems and infrastructure.

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•	technological changes and network expansions, which have resulted in increased transmission capacity available for sale by us and by our competitors; and

•	some of our competitors have been willing to accept smaller operating margins in the short term in an attempt to increase long-term revenue.

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•	demands on management related to any significant increase in size after the acquisition;

•	the disruption of ongoing business and the diversion of management’s attention from the management of daily operations to management of integration activities;

•	failure to fully achieve expected synergies and costs savings;

•	unanticipated impediments in the integration of departments, systems, including accounting systems, technologies, books and records and procedures, as well as in maintaining uniform standards, controls, including internal control over financial reporting required by the Sarbanes-Oxley Act, procedures and policies;

•	loss of customers or the failure of customers to order incremental services that we expect them to order;

•	failure to provision services that are ordered by customers during the integration period;

•	higher integration costs than anticipated; and

•	difficulties in the assimilation and retention of highly qualified, experienced employees, many of whom may be geographically dispersed.

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•	price and volume fluctuations in the overall stock market from time to time;

•	volatility in the trading prices and trading volumes of technology stocks;

•	volatility in the trading volumes of our Class A common stock;

•	changes in operating performance and stock market valuations of other technology companies generally, or those in our industry in particular;

•	sales of shares of our Class A common stock by us or our stockholders;

•	failure of securities analysts to maintain coverage of us, changes in financial estimates by securities analysts who follow our company, or our failure to meet these estimates or the expectations of investors;

•	the financial projections we may provide to the public, any changes in those projections or our failure to meet those projections;

•	announcements by us or our competitors of new products or services;

•	the public’s reaction to our press releases, other public announcements and filings with the SEC;

•	rumors and market speculation involving us or other companies in our industry;

•	actual or anticipated changes in our results of operations or fluctuations in our results of operations;

•	actual or anticipated developments in our business, our competitors’ businesses or the competitive landscape generally;

•	litigation involving us, our industry or both;

•	regulatory actions or developments affecting our operations, those of our competitors or our industry more broadly;

•	developments or disputes concerning our intellectual property or other proprietary rights;

•	announced or completed acquisitions of businesses, products, services or technologies by us or our competitors;

•	new laws or regulations or new interpretations of existing laws or regulations applicable to our business;

•	changes in accounting standards, policies, guidelines, interpretations or principles;

•	new rules adopted by certain index providers, such as S&P Dow Jones, that limit or preclude inclusion of companies with multi-class capital structures in certain of their indices;

•	any significant change in our management; and

•	general economic conditions and slow or negative growth of our markets.

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•	authorizing “blank check” preferred stock, which could be issued by our board of directors without stockholder approval and may contain voting, liquidation, dividend and other rights superior to our Class A and Class B common stock;

•	limiting the liability of, and providing indemnification to, our directors and officers;

•	limiting the ability of our stockholders to call and bring business before special meetings;

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providing for a dual class common stock structure in which holders of our Class B common stock have the ability to control the outcome of matters requiring stockholder approval, even if they own significantly less than a majority of the outstanding shares of our Class A and Class B common stock, including the election of directors and significant corporate transactions, such as a merger or other sale of our company or its assets;

•	providing that our board of directors is classified into three classes of directors with staggered three-year terms;

•	prohibiting stockholder action by written consent, which requires all stockholder actions to be taken at a meeting of our stockholders;

•	requiring super-majority voting to amend some provisions in our second amended and restated certificate of incorporation and second amended and restated bylaws;

•	requiring advance notice of stockholder proposals for business to be conducted at meetings of our stockholders and for nominations of candidates for election to our board of directors; and

•	controlling the procedures for the conduct and scheduling of board of directors and stockholder meetings.

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•	depreciation and amortization; and

•	stock-based compensation.

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•	income tax provision (benefit);

•	interest expense, net;

•	depreciation and amortization expense;

•	stock-based compensation expense;

•	impairment of intangible assets, if any; and

•	loss (gain) on disposal of property and equipment.

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•	stock-based compensation;

•	amortization of acquired intangible assets related to the Dash acquisition;

•	impairment charges of intangibles assets, if any;

•	loss (gain) on disposal of property and equipment;

•	estimated tax impact of above adjustments;

•	benefit resulting from the release of the valuation allowance on our deferred tax assets (DTA); and

•	impact of remeasurement of DTA as a result of 2017 tax reform act

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Item 7.	Management's Discussion and Analysis of Financial Condition and Results of Operations

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Fair value of our common stock. The fair value of the shares of our common stock underlying stock options had historically been established by our board of directors with the assistance of an independent third-party valuation firm. Because there had been no public market for our common stock, our board of directors had relied on this independent valuation and other factors to establish the fair value of our common stock at the time of grant of the option. The determination of the fair value of our common stock is discussed further below.

•	Expected term. The expected term was estimated using the simplified method allowed under SEC guidance as we do not have sufficient historical data to use any other method to estimate the expected term.

•	Expected volatility. The expected volatility is derived from an average of the historical volatilities of the common stock of several entities with characteristics similar to ours, such as the size, and operational and economic similarities to our principle business operations. We use this method because we have limited information on the volatility of our common stock.

•	Risk-free interest rate. The risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the options for each option group.

•	Expected dividends. The expected dividend is assumed to be zero as we have never paid dividends and have no current plans to pay any dividends on our common stock.

•	contemporaneous unrelated third-party valuations of our common stock;

•	the rights, preferences and privileges of our redeemable convertible preferred stock relative to those of our common stock;

•	our results of operations, financial position and capital resources;

•	current business conditions and projections;

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•	the lack of marketability of our common stock;

•	the hiring of key personnel and the experience of our management;

•	the introduction of new products;

•	the risk inherent in the development and expansion of our products;

•	the fact that the option grants involve illiquid securities in a private company;

•	the likelihood of achieving a liquidity event, such as an initial public offering or a sale of our company, given the prevailing market conditions;

•	industry trends and competitive environment; and

•	overall economic indicators, including gross domestic product, employment, inflation and interest rates.

•	The income approach estimates value based on the expectation of future cash flows that a company will generate. These future cash flows are discounted to their present values using a discount rate derived from an analysis of the cost of capital of comparable publicly traded companies in our industry as of each valuation date and is adjusted to reflect the risks inherent in our cash flows.

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The market approach estimates value based on a comparison of the subject company to comparable public companies in a similar line of business. From the comparable companies, a representative market value multiple is determined and then applied to the subject. The estimated value for our common stock is then discounted by a non-marketability factor (discount for lack of marketability) due to the fact that stockholders of private companies do not have access to trading markets similar to those enjoyed by stockholders of public companies, which affects liquidity.

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Item 7A.	Quantitative and Qualitative Disclosures about Market Risk

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Fair value of our common stock. Prior to the Company's IPO, the fair value of the shares of the Company's common stock underlying stock options has historically been established by the board of directors. Numerous objective and subjective factors that were considered included, but were not limited to, the following: i) contemporaneous independent, third-party valuations of the Company's common stock; ii) the rights, preferences and privileges of the Company's redeemable convertible preferred stock relative to those of the Company's common stock; iii) the Company's results of operations, financial position and capital resources; iv) current business conditions and projections; v) the lack of marketability of the Company's common stock; vi) the hiring of key personnel and the experience of the Company's management; vi) the introduction of new products; vii) the risk inherent in the development and expansion of the Company's products; viii) the fact that the option grants involve illiquid securities in a private company; ix) the likelihood of achieving a liquidity event, such as an initial public offering or a sale of the Company, given the prevailing market conditions; x) industry trends and competitive environment; and xi) overall economic indicators, including gross domestic product, employment, inflation and interest rates. After the IPO, the Company uses the market closing price of its Class A common stock as reported on the NASDAQ Global Select Market for the fair value.

•	Expected term. The expected term was estimated using the simplified method allowed under SEC guidance as the Company does not have sufficient historical data to use any other method to estimate the expected term.

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•	Expected volatility. The expected volatility is derived from an average of the historical volatilities of the common stock of several entities with characteristics similar to those of the Company, such as the size, and operational and economic similarities to its principle business operations. The Company uses this method because it has limited information on the volatility of its common stock.

•	Risk-free interest rate. The risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the options for each option group as of the grant date.

•	Expected dividends. 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.

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•	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.

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•	closing of a “Qualified Public Offering,” which is defined as one resulting in aggregate net proceeds to the Company equal to or greater than $20 million, or

•	a “true sale” as defined in the Investors’ Rights Agreement.

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(a)	The following documents are filed as part of this report:

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1.	Financial Statements

2.	Financial Statement Schedules

3.	Exhibits

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*	The certifications furnished in Exhibit 32.1 hereto are deemed to accompany this Annual Report on Form 10-K and will not be deemed "filed" for purpose of Section 18 of the Securities Exchange Act of 1934, as amended, except to the extent that the registrant specifically incorporates by reference