Filed pursuant to Rule 424(b)(5)
Registration No. 333-254440

PROSPECTUS SUPPLEMENT

(To prospectus dated April 12, 2021)

Up to $41,636,612

Common Stock, par value $0.001 per share

This prospectus supplement is being filed to update, amend and supplement certain information in the prospectus of Sonim Technologies, Inc., dated April 12, 2021 (the “Base Prospectus”) as supplemented by the prospectus supplement dated June 30, 2021 (including any documents incorporated by reference therein) (the “Prior Prospectus Supplement”).

We have entered into a sales agreement (the “Sales Agreement”), dated September 23, 2021, with B. Riley Securities, Inc. (“B. Riley Securities” or the “Agent”), pursuant to which, we may offer and sell, from time to time, shares of our common stock, par value $0.001 per share (the “Shares”) to or through the Agent, as sales agent or principal, as described in this prospectus supplement and the accompanying prospectus. Pursuant to the terms of the Sales Agreement, we may now, through the Agent, offer and sell, from time to time, up to an aggregate amount of $41,636,612 of Shares.

From June 30, 2021 through September 22, 2021, we issued and sold Shares having an aggregate amount of approximately $8,363,388, after deducting commissions to B. Riley Securities and EF Hutton, division of Benchmark Investment, LLC on the Shares sold and offering expenses. As a result, as of September 22, 2021, Shares with an aggregate amount of approximately $41,636,612 remain available for sale under the Base Prospectus, the Prior Prospectus Supplement and this prospectus supplement.

Our common stock is listed on The Nasdaq Capital Market under the symbol “SONM.” On September 22, 2021, the last reported sale price of our common stock was $3.27 per share.

The securities to which this prospectus supplement and the accompanying prospectus relate will be offered and sold through the Agent over a period of time and from time to time by any method that is deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended (the “Securities Act”). The Agent is not required to sell any specific number of Shares, but will act as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed terms between the Agent and us. Under the Sales Agreement, the Agent will be entitled to compensation of up to 3.00% of the gross sales price of all Shares sold. In connection with the sale of Shares on our behalf, the Agent will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of the Agent will be deemed to be underwriting commissions or discounts. The amount of net proceeds we will receive from this offering, if any, will depend upon the number of Shares sold and the market price at which such Shares are sold. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and net proceeds to us, if any, are not determinable at this time. There is no arrangement to place proceeds of the offering in escrow, trust or similar arrangement. See “Plan of Distribution.”

Investing in the Shares involves a high degree of risk. You should carefully consider the risks described under “Risk Factors” beginning on page S-8 of this prospectus supplement and in the documents incorporated by reference in this prospectus supplement and the accompanying prospectus.

Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

B. Riley Securities

The date of this prospectus supplement is September 24, 2021.

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS SUPPLEMENT		S-1
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS		S-2
PROSPECTUS SUPPLEMENT SUMMARY		S-4
THE OFFERING		S-7
RISK FACTORS		S-8
USE OF PROCEEDS		S-14
DILUTION		S-15
DESCRIPTION OF OUR CAPITAL STOCK		S-17
MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERS OF OUR COMMON STOCK		S-21
PLAN OF DISTRIBUTION		S-25
LEGAL MATTERS		S-27
EXPERTS		S-28
INFORMATION INCORPORATED BY REFERENCE		S-29
WHERE YOU CAN FIND MORE INFORMATION		S-30

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ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying prospectus are part of a registration statement that we filed with the Securities and Exchange Commission (“SEC”) utilizing a “shelf” registration process. This document is in two parts. The first part is this prospectus supplement, including the documents incorporated by reference, which describes the specific terms of this offering. The second part, the accompanying prospectus, including the documents incorporated by reference, provides more general information. Generally, when we refer to this prospectus, we are referring to both parts of this document combined. We urge you to carefully read this prospectus supplement and the accompanying prospectus, and the documents incorporated by reference herein and therein, before buying any of the securities being offered under this prospectus supplement. This prospectus supplement may add or update information contained in the accompanying prospectus and the documents incorporated by reference therein. To the extent that any statement we make in this prospectus supplement is inconsistent with statements made in the accompanying prospectus or any documents incorporated by reference therein that were filed before the date of this prospectus supplement, the statements made in this prospectus supplement will be deemed to modify or supersede those made in the accompanying prospectus and such documents incorporated by reference therein.

You should rely only on the information contained in this prospectus supplement and the accompanying prospectus, or incorporated by reference herein or therein. Neither we nor the Agent have authorized anyone to provide you with different information. No dealer, salesperson or other person is authorized to give any information or to represent anything not contained in this prospectus supplement and the accompanying prospectus. You should not rely on any unauthorized information or representation. This prospectus supplement is an offer to sell only the securities offered hereby, and only under circumstances and in jurisdictions where it is lawful to do so. You should assume that the information in this prospectus supplement and the accompanying prospectus is accurate only as of the date on the front of the applicable document and that any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference, regardless of the date of delivery of this prospectus supplement or the accompanying prospectus, or any sale of a security.

As used in this prospectus, unless the context indicates or otherwise requires, “the Company,” “Sonim,” “we,” “us” or “our” refer to the combined business of Sonim Technologies, Inc. and its consolidated subsidiaries.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein contain forward-looking statements within the meaning of Section 27A of the Securities Act, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). We have based these forward-looking statements on our current expectations and projections about future events or future financial performance, which include, but are not limited to, statements regarding our business strategies, growth prospects, operating and financial performance, plans, estimates and projections. These statements are based on management’s current expectations and beliefs and on information currently available to us.

In some cases, you can identify forward-looking statements by the following words: “may,” “will,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “ongoing” or the negative of these terms or other comparable terminology, although not all forward-looking statements contain these words. These statements involve risks, uncertainties and other factors that may cause actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements, including but not limited to:

• Our anticipated use of the proceeds from this offering;

• There is substantial doubt about our ability to continue as a going concern and we may not be able to improve our liquidity or financial position;

• We may not be able to continue to develop solutions to address user needs effectively, including our next generation products, which would materially adversely affect our liquidity and our ability to continue operations;

• We have not been profitable in recent years and may not achieve or maintain profitability in the future;

• We rely on our channel partners to generate a substantial majority of our revenues;

• A small number of customers account for a significant portion of our revenue;

• We are materially dependent on some customer relationships that are characterized by product award letters and the loss of such relationships could harm our business and operating results;

• Our business is difficult to evaluate because we have a limited operating history in our markets;

• We continue to restructure and transform our business and there is no guarantee that our restructuring or transformation will be successful or achieve the desired results;

• Our quarterly results may vary significantly from period to period;

• We rely primarily on third-party contract manufacturers and partners;

• If our products contain defects or errors, we could incur significant unexpected expenses, experience product returns and lost sales, experience product recalls, suffer damage to our brand and reputation, and be subject to product liability or other claims;

• We are required to undergo a lengthy customization and certification process for each wireless carrier customer;

• We previously announced that we will be looking at strategic initiatives, but there is no assurance that any of these initiatives will be successful, and we may be required to substantially downsize our operations and our research and development;

• Our dependence on third-party suppliers for key components of our products could delay shipment of our products and reduce our sales;

• We are dependent on the continued services and performance of a concentrated and limited group of senior management and other key personnel;

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• We face risks related to health epidemics, pandemics and other outbreaks, including the COVID-19 pandemic;

• Changes in laws and regulations concerning the use of telecommunication bandwidth could increase our costs and adversely impact our business;

• If we are unable to successfully protect our intellectual property, our competitive position may be harmed;

• Others may claim that we infringe on their intellectual property rights, which may result in costly and time-consuming litigation and could delay or otherwise impair the development and commercialization of our products;

• We have identified one material weakness in our internal control over financial reporting which, if not remediated, could result in material misstatements in our financial statements; and

• We have failed, and may continue to fail, to meet the listing standards of the Nasdaq Capital Market (“Nasdaq”), and as a result our common stock may become delisted.

These statements are based on the beliefs and assumptions of our management and on information currently available to our management. Our actual results, performance and achievements may differ materially from the results, performance and achievements expressed or implied in such forward-looking statements. For a discussion of some of the factors that might cause such a difference, see the “Risk Factors” contained in Part I, Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2020, as amended, and our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021, as amended, and June 30, 2021. Except as required by law, we specifically disclaim any obligation to update such forward-looking statements.

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PROSPECTUS SUPPLEMENT SUMMARY

This summary is not complete and does not contain all of the information that you should consider before investing in the securities offered by this prospectus supplement and accompanying prospectus. You should read this summary together with the entire prospectus supplement and the accompanying prospectus, including our consolidated financial statements, the Shares to those consolidated financial statements and the other documents that are incorporated by reference in this prospectus supplement and the accompanying prospectus, before making an investment decision. See “Risk Factors” beginning on page S-8 of this prospectus supplement, along with the risk factors in our Annual Report on Form 10-K for the year ended December 31, 2020, as amended, and our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021, as amended, and June 30, 2021, which are incorporated by reference herein, for a discussion of the risks involved in investing in our securities.

Our Business

Sonim Technologies, Inc. was incorporated in the state of Delaware on August 5, 1999 and is headquartered in Austin, Texas. Unless otherwise indicated, the terms “we,” “us,” “our,” “Company” and “Sonim” refer to Sonim Technologies, Inc. and its wholly owned and consolidated subsidiaries.

We are a leading U.S. provider of ultra-rugged mobile phones and accessories designed specifically for task workers physically engaged in their work environments, often in mission-critical roles. We currently sell our ruggedized mobile phones and accessories to the three largest wireless carriers in the United States—AT&T, T-Mobile and Verizon—as well as the three largest wireless carriers in Canada—Bell, Rogers and Telus Mobility. Our phones and accessories connect workers with voice, data, and workflow applications in two end-markets: industrial enterprise and public sector. In 2020, we announced that we would be entering the ruggedized barcode scanner business and we began shipping our first devices in March 2021. Our barcode scanner devices, as well as our ruggedized phones and accessories, are sold through distributors in North America, South America and Europe.

Task workers in these end markets have historically been limited to pen and paper and single-purpose electronic devices, such as barcode scanners, location-tracking devices and sensors, to accomplish specific tasks. These single-purpose devices have historically run on proprietary networks, such as Land Mobile Radio (LMR) networks that enable Push-to-Talk (PTT) services for voice communications. We provide Android-based devices that consolidate and integrate multiple functions into a single ruggedized solution running on commercial wireless networks at a total cost of ownership that we believe is significantly lower with improved productivity and safety of task workers.

At the beginning of 2021, we outsourced substantially all of our software development to a third-party and transferred 105 employees to support the work to be performed. In connection with outsourcing our software development, the Company entered into an agreement of future business volume over the next three years in the amount of $7.1 million, of which the Company has committed that a minimum value of $3.1 million shall be assured in the first year of business. The Company paid $1.8 million under the agreement during the first six months ended June 30, 2021.

Additionally, in the beginning of 2021, we outsourced our manufacturing work to a supply chain partner and ultimately transferred or eliminated 22 employees as part of this solution. Our worldwide employee count at June 30, 2021, was 85.

Our solutions consist primarily of ultra-rugged mobile phones based on the Android platform which are capable of attaching to both public and private wireless networks, industrial-grade accessories that meet the requirements of specific applications, and software applications and cloud-based tools that provide management and deployment services to our customers. Beginning in the three months ended March 31, 2021, we entered the

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rugged handheld and tablet market with our new SmartScanner products. The Sonim RS80, an Android-based tablet that is certified as Android Enterprise Recommended by Google, became available in February and all available inventory had been shipped by the end of the first quarter. Additionally, the Sonim RS60, an Android-based handheld computer and LTE device that is certified as Android Enterprise Recommended by Google, became available for shipment in June. On June 30, 2021, we announced the Sonim RT80, an Android-based tablet that differs from the RS80 by not having an integrated barcode scanner. In September 2021, we launched the first of our next generation products, the XP3plus. We anticipate launching our next two next generation products in 2022.

End customers of our solutions include construction, energy and utility, hospitality, logistics, manufacturing, public sector and transportation entities that primarily purchase our devices and accessories through their wireless carriers. The key attributes of our solutions are specifically tailored for the needs of our end users, including impact resistance, waterproof and dustproof construction, extended battery life and extra loud audio, supported by a three-year comprehensive warranty. All of our devices run on the Android operating system, providing a familiar and intuitive user interface, and our smartphones have access to a library of millions of applications available through the Google Play Store. We have also implemented dozens of application programming interfaces, or APIs, specific to our mobile phones and have partnered with third-party application developers to create a purpose-built experience for our end users using these applications on our mobile phones.

We currently have stocked product with the three largest U.S. wireless carriers: AT&T, T-Mobile (which acquired Sprint in 2020) and Verizon, meaning that these carriers test and certify our mobile phones on their networks and maintain inventory in their warehouses that they then sell through their enterprise and retail sales teams to end customers, often on a subsidized or financed basis. Our full product portfolio has been stocked with the three largest Canadian wireless carriers since 2015. In 2020, we sold approximately 33,000 mobile phones in Canada and 216,000 in the United States (which markets include rugged feature phones, smart consumer rugged phones, smart ultra-rugged phones and life-proofed smart phones).

We enter into master sales arrangements with carriers (including channel partners contributing over 93% of our total revenues for the three months ended June 30, 2021) under which our partners purchase our solutions for distribution on a purchase order basis. Under these arrangements, we and the channel partners determine sales channel distribution in connection with pricing (including any discounts and price protection) and market positioning of each particular mobile phone product. We also offer our channel partners channel marketing and other promotional incentives, such as sales volume incentives, in exchange for retail price reductions. We may also offer Non-recurring Engineering (NRE) services in the form of third-party design services relating to the design of materials and software licenses used in the manufacturing of our products.

Corporate Information

We are incorporated under the laws of the State of Delaware. Our principal executive offices are located at 6500 River Place Boulevard, Bldg. 7, S#250, Austin, Texas 78730. Our telephone number is (650) 378-8100. Our website is https://www.sonimtech.com. The information contained on or accessible through our website is not part of this prospectus supplement. The documents that we file with the SEC that are incorporated by reference into this prospectus supplement are accessible on our website.

Reverse Stock Split

On September 15, 2021, we filed a Certificate of Amendment to our Amended and Restated Certificate of Incorporation to effect a one-for-ten reverse stock split (the “Reverse Stock Split”) of the outstanding shares of our common stock. As a result of the Reverse Stock Split, every ten (10) shares of our issued common stock were converted into one (1) issued share of our common stock, without any change to the par value of our common stock or the authorized number of shares of our common stock. Stockholders who would otherwise be entitled to a fractional share of our common stock are instead entitled to receive cash (rounded down to the nearest cent,

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without interest and subject to applicable withholding taxes) in lieu of such fractional share. All share numbers and per share amounts in this prospectus supplement have been retroactively adjusted to reflect the Reverse Stock Split.

Additional Information

For additional information about us, please refer to the documents set forth under “Information Incorporated by Reference” in this prospectus supplement, including our Annual Report on Form 10-K for the year ended December 31, 2020, as amended, and our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021, as amended, and June 30, 2021, which are incorporated by reference herein.

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THE OFFERING

The following is a brief summary of some of the terms of the offering and is qualified in its entirety by reference to the more detailed information appearing elsewhere in this prospectus supplement and the accompanying prospectus. For a more complete description of the terms of the Shares, see the “Description of the Shares” section in this prospectus supplement.

Issuer Sonim Technologies, Inc.

Common Stock Offered Up to $41,636,612 of shares of our Common Stock, par value $0.001 per share (the “Shares”).

Manner of Offering “At the market offering” that may be made from time to time to or through the Agent, as sales agent or principal, subject to our instruction as to amount and timing. The Agent is not required to sell any specific number of Shares, but the Agent will make all sales using commercially reasonable efforts consistent with its normal trading and sales practices on mutually agreed terms between the Agent and us. See “Plan of Distribution” on page S-22.

Listing The Shares are listed on the Nasdaq Capital Market under the symbol “SONM”.

Use of Proceeds We anticipate using the net proceeds from this offering to fund ongoing operations. Pending such use, we may invest the net proceeds in short-term interest-bearing accounts, securities or similar investments. See “Use of Proceeds.”

Risk Factors An investment in the Shares involves significant risks. Please refer to “Risk Factors” beginning on page S-8 and other information included or incorporated by reference in this prospectus supplement and the accompanying prospectus for a discussion of factors you should carefully consider before investing in the Shares.

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RISK FACTORS

An investment in the Shares involves significant risks, including the risks described below and discussed under the section captioned “Risk Factors” contained in our annual report on Form 10-K for the year ended December 31, 2020, as amended, and our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021, as amended, and June 30, 2021, as updated by our subsequent filings under the Exchange Act, which are incorporated by reference in this prospectus supplement and the accompanying prospectus in their entirety. Before purchasing the Shares, you should carefully consider each of the following risk factors as well as the other information contained in this prospectus supplement and the accompanying prospectus and the documents incorporated by reference, including our consolidated financial statements and the related notes. Each of these risk factors, either alone or taken together, could materially and adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in the Shares. The risks described below are not the only ones we face. Additional risks of which we are not presently aware or that we currently believe are immaterial which may also impair our business operations and financial position. If any of the events described below were to occur, our financial condition, our results of operations and/or our future growth prospects could be materially and adversely affected. As a result, you could lose some or all of any investment you may have made or may make in our Company.

Risks Related to our Business

You should read and consider the significant risk factors specific to our business before making an investment decision. Those risks are described in the section entitled “Risk Factors—Risks Relating to Our Business” in our Annual Report on Form 10-K for the year ended December 31, 2020, as amended, and our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021, as amended, and June 30, 2021. Please be aware that additional risks and uncertainties not currently known to us or that we currently deem immaterial could also materially and adversely affect our business, results of operations, financial condition, cash flows, prospects or the value of our common stock.

There is substantial doubt about our ability to continue as a going concern. We may need substantial additional funding beyond the proceeds of this offering and may be unable to raise capital when needed.

There is substantial doubt about our ability to continue as a going concern. If we are unable to raise sufficient capital in this offering or otherwise as and when needed, our business, financial condition and results of operations will be materially and adversely affected. Even if we are successful in completing this offering, it is not certain whether the capital raised in this offering will be sufficient to continue as a going concern and we may not be able to raise additional capital when needed. If we are unable to continue as a going concern, we may have to liquidate our assets, and the values we receive for our assets in liquidation or dissolution could be significantly lower than the values reflected in our financial statements. Our lack of cash resources and our potential inability to continue as a going concern may materially adversely affect our share price and our ability to raise new capital, enter into critical contractual relations with third parties and otherwise execute our development strategy.

We are actively managing our liquidity and expenses, including by extending payables due and pausing or reducing investment in our next generation products, and it is not certain that we will be ultimately successful in developing our next generation products and remaining a going concern.

We are actively managing our liquidity and expenses, including by extending the term of payables due, and there is substantial doubt that our current cash position, even if this offering is successful, will be sufficient to fully develop our next generation products. Our liquidity has been significantly and negatively impacted by a decline in the sales of our legacy products while our next generation products remain under development, and we have an accumulated deficit of $212.1 million as of June 30, 2021.

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As of September 22, 2021, we had approximately $6.1 million in cash and cash equivalents and $6.2 million in accounts receivable that we anticipate we will be successful in collecting within the next 30 days, compared to approximately $6.9 million and $6.3 million as of June 30, 2021, respectively. As of September 22, 2021, we also had approximately $12.6 million in accounts payable, compared to approximately $16.3 million as of June 30, 2021. We are also continuing to incur expenses that will cause us to expend cash in the short-term, including as a result of our ongoing SEC investigation, as disclosed in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2021. As a result of our current liquidity, to date we have slightly reduced and delayed, and if we are unable to raise sufficient capital, we may have to significantly reduce or delay, investment in developing our new generation products, and we may not be successful in developing our next generation products without raising further capital subsequent to the conclusion of this offering. If we are unable to develop our next generation products in a timely or cost-effective manner, it is likely that we will cease to be a going concern and may have to liquidate our assets, which could result in a total loss of your investment.

We have identified a material weakness in our internal control over financial reporting and our management concluded that our internal control over financial reporting was not effective as of December 31, 2020, which, if not remediated, could result in material misstatements in our financial statements. In addition, our management concluded that our disclosure controls and procedures were not effective as of June 30, 2021, which, if not remediated, could result in material misstatements in our financial statements and other disclosure failures. We may be unable to develop, implement and maintain appropriate controls and procedures in future periods.

A material weakness is a deficiency, or combination of deficiencies, in internal control over financial reporting such that there is a reasonable possibility that a material misstatement of our annual or interim consolidated financial statements may not be prevented or detected on a timely basis. As disclosed in our Form 10-K for the year ended December 31, 2020, as amended, as of December 31, 2020, we identified one material weakness in internal control over financial reporting that pertains to a deficiency in the design and implementation of ITGCs, including elevated (administrator) access to financial reporting systems and subsystems, which are not appropriately restricted and segregated. Our management concluded that, as of December 31, 2020, our internal control over financial reporting was not effective and also concluded that, as of June 30, 2021, our disclosure controls and procedures were not effective.

Although we have developed and implemented a plan to remediate the material weakness and the effectiveness of our disclosure controls and procedures, and believe that the foregoing will be remediated in a timely fashion, we cannot assure you that this will occur within a specific timeframe. The material weakness and disclosure controls and procedures will not be remediated until all necessary internal controls and procedures have been designed, implemented, tested and determined to be operating effectively. In addition, we may need to take additional measures to address the material weakness and disclosure controls and procedures or modify the planned remediation steps, and we cannot be certain that the measures we have taken, and expect to take, to improve our internal controls and disclosure controls and procedures will be sufficient to address the issues identified, to ensure that our internal controls and disclosure controls and procedures are effective or to ensure that the identified material weakness or ineffective disclosure controls and procedures will not result in a material misstatement of our consolidated financial statements. Moreover, we cannot assure you that we will not identify additional material weakness in our internal control over financial reporting in the future.

Until we remediate the material weakness and until our disclosure controls and procedures are effective, our ability to record, process and report financial information accurately, and to prepare financial statements within the time periods specified by the rules and forms of the SEC, could be adversely affected. This failure could negatively affect the market price and trading liquidity of our common units, cause investors to lose confidence in our reported financial information, subject us to civil and criminal investigations and penalties and generally materially and adversely impact our business and financial condition.

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We have failed, and may continue to fail, to meet the listing standards of Nasdaq, and as a result our common stock may become delisted, which could have a material adverse effect on the liquidity of our common stock.

The listing standards of the Nasdaq Capital Market provide that a company, in order to qualify for continued listing, must maintain a minimum closing bid price of $1.00 and satisfy standards relative to minimum stockholders’ equity, minimum market value of publicly held shares and various additional requirements. On April 29, 2021, we received a deficiency letter from the Listing Qualifications Department (the “Staff”) of Nasdaq notifying us that, for the last 30 consecutive business days, the bid price for our common stock had closed below the minimum $1.00 per share requirement for continued inclusion on the Nasdaq Capital Market.

In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we have been provided a period of 180 calendar days, or until October 25, 2021, in which to regain compliance. In order to regain compliance with the minimum bid price requirement, the closing bid price of our common stock must be at least $1.00 per share for a minimum of ten consecutive business days during this 180-day period. In the event that we do not regain compliance within this 180-day period, we may be eligible to seek an additional compliance period of 180 calendar days if we (i) meet the continued listing requirement for market value of publicly held shares and all other initial listing standards for the Nasdaq Capital Market, with the exception of the bid price requirement, and (ii) provide written notice to Nasdaq of our intent to cure the deficiency during this second compliance period, including by effecting the Reverse Stock Split. However, if it appears to the Staff that we will not be able to cure the deficiency, or if we are otherwise not eligible, Nasdaq will provide notice to us that we will not be eligible for the additional compliance period and our common stock will be subject to delisting. We would then be entitled to appeal the determination to a Nasdaq Listing Qualifications Panel and request a hearing.

On September 15, 2021, we filed a Certificate of Amendment to our Amended and Restated Certificate of Incorporation to effect the Reverse Stock Split. As a result of the Reverse Stock Split, every ten (10) shares of our issued common stock were converted into one (1) issued share of our common stock, without any change to the par value of our common stock or the authorized number of shares of our common stock, although there can be no assurance that we will be able to regain compliance with the minimum bid price requirement or maintain compliance with the other Nasdaq listing requirements. If we do not regain compliance with the Nasdaq continuing listing requirements, our common stock will be delisted from the Nasdaq Capital Market and it could be more difficult to buy or sell our securities and to obtain accurate quotations, and the price of our common stock could suffer a material decline. In addition, a delisting would impair our ability to raise capital through the public markets, could deter broker-dealers from making a market in or otherwise seeking or generating interest in our securities and might deter certain institutions and persons from investing in our securities at all.

We may not be able to continue to develop solutions to address user needs effectively, including our next generation products, which would materially adversely affect our liquidity and our ability to continue operations.

Our industry is characterized by:

• evolving industry standards;

• frequent new product and service introductions;

• evolving distribution channels;

• increasing demand for customized product and software solutions;

• rapid competitive developments; and

• changing customer demands.

Technological advancements could render our products obsolete, which typically erodes prices and causes products to become unmarketable. Our success will depend on our ability to respond to changing technologies and customer requirements, and our ability to develop and introduce new and enhanced products in a cost-effective and timely manner. For example, our products are compatible with fourth generation, or 4G,

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technology, but emerging fifth generation wireless, or 5G, technology is expected to require network infrastructure upgrades, which could require us to update and migrate all of our systems from 4G to 5G. In addition, several of our legacy products are nearing or have reached the end of their product lifecycle and are becoming obsolete due to technological advancements and ongoing change in the industry. As a result, we have experienced significant declines in revenue in recent quarters due to a drop in the number of unit sales of these legacy handheld devices. For example, during the six months ended June 30, 2021, the number of unit sales of our legacy rugged handheld devices decreased by 65,952, or 44%, compared to the six months ended June 30, 2020, primarily as a result of these products reaching the end of their product lifecycle.

As a result, we are currently prioritizing spending on research and development of our next generation ruggedized mobile phones. In September 2021, we launched the first of our next generation products, the XP3plus. We anticipate launching our next two next generation products in 2022. However, the research and development necessary to launch our remaining next generation products will require us to incur additional costs and our liquidity continues to be adversely impacted by our ongoing net losses. There can be no assurance that we will have sufficient resources to complete the development of our next generation ruggedized mobile phones and bring them to market. Even if we are able to introduce our remaining next generation ruggedized mobile phones to the market, there can be no assurance that these new product introductions will lead to any sales or increase in revenue. If we fail to develop these next generation products or enhancements on a timely and cost-effective basis, or if our new products or enhancements fail to achieve market acceptance, our business, operations, financial condition and liquidity would be further materially adversely affected and we may be required to delay, reduce or cease our operations and we may be required to seek bankruptcy protection. See above under “We are actively managing our liquidity and expenses, including by extending payables due and pausing or reducing investment in our next generation products, and it is not certain that we will be ultimately successful in developing our next generation products and remaining a going concern.”

Further, the development of new or enhanced products is a complex and uncertain process requiring the accurate anticipation of technological and market trends. We may experience design, manufacturing, marketing, and other difficulties that could delay or prevent the development, introduction or marketing of our new products and enhancements. If we experience delays with new products, if our expectations regarding market demand and direction are incorrect, if sales of our existing products begin to decline more rapidly, or if the rate of decline continues to exceed the rate of growth of our next generation products, it will materially and adversely affect our business, results of operations and financial condition, and may require us to significantly reduce or even eliminate certain research and development programs.

We are dependent on the continued services and performance of a concentrated and limited group of senior management and other key personnel, the loss of any of whom could adversely impact our business.

Our future success depends in large part on the continued contributions of a concentrated and limited group of senior management and other key personnel. As previously disclosed, beginning in 2021, we outsourced substantially all of our software development and manufacturing work to third parties and, as part of these outsourcings, we transferred or eliminated a significant number of employees. As of June 30, 2021, our worldwide employee headcount was 85 employees, down from 317 employees at December 31, 2020, and 500 employees at December 31, 2019. Our senior management team is also small, with Mr. Robert Tirva serving as our President, Chief Operating Officer and Chief Financial Officer as of May 31, 2021. We currently have no Chief Executive Officer.

Due to the small size of our Company and our limited number of employees, each member of our executives, managers and other key personnel serve a critical role to our success. If we are unable to retain sufficiently experienced and capable employees, including those who can help us increase revenues generated from our end market segments, our business and financial results may suffer. The loss of the services of any additional executives, managers or other key personnel could impede the achievement of our strategic objectives, seriously harm our ability to successfully implement our business strategy and adversely impact our operating results. In addition, if additional executives, managers or other key personnel resign, retire or are terminated, or their service is otherwise interrupted, including due to COVID-19, we may not be able to replace them in a

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timely manner and we could experience significant declines in productivity and/or errors due to insufficient staffing or managerial oversight. Moreover, experienced and capable employees in the technology industry remain in high demand, and there is continual competition for their talents. Given our size, we may be at a disadvantage, relative to our larger competitors, in the competition for these personnel.

We cannot assure you that our exploration of strategic and financing alternatives will result in a transaction and/or financing or that any such transaction or financing would be successful, or that any resulting plans or transactions will yield additional value for shareholders, and the process of exploring strategic and financing alternatives or its conclusion could adversely impact our business and our stock price.

In August 2021, we announced that we had initiated a review of our strategic alternatives and capital market options, including buy and sell side opportunities. This process is ongoing, and we have engaged B. Riley Securities to assist in the process.

There can be no assurances that the strategic and financing alternatives process will result in the announcement or consummation of any strategic or financing transaction, or that any resulting plans or transactions will yield additional value for shareholders. Any potential transaction would be dependent on a number of factors that may be beyond our control, including, among other things, market conditions, industry trends, the interest of third parties in any potential transaction with the Company.

The process of exploring strategic and financial alternatives could adversely impact our business, financial condition and results of operations. We could incur substantial expenses associated with identifying and evaluating potential strategic and financing alternatives, including those related to equity compensation, severance pay and legal, accounting and financial advisory fees. In addition, the process may be time consuming and disruptive to our business operations, could divert the attention of management and the board of directors from our business, could negatively impact our ability to attract, retain and motivate key employees, and could expose us to potential litigation in connection with this process or any resulting transaction. The public announcement of a strategic or financing alternative may also yield a negative impact on operating results if prospective or existing customers are reluctant to commit to new products or if existing customers decide to shift their business to a competitor. Further, speculation regarding any developments related to the review of strategic or financial alternatives and perceived uncertainties related to the future of the Company could cause our stock price to fluctuate significantly.

Risks Related to this Offering

We will have broad discretion in the use of our existing cash and cash equivalents, including the proceeds from this offering, and may invest or spend our cash in ways with which you do not agree and in ways that may not increase the value of your investment.

We will have broad discretion over the use of our cash and cash equivalents, including the proceeds from this offering. You may not agree with our decisions, and our use of cash may not yield any return on your investment. Our failure to apply the net proceeds from this offering effectively could compromise our ability to pursue our growth strategy and we might not be able to yield a significant return, if any, on our investment of these net proceeds. You will not have the opportunity to influence our decisions on how to use our net proceeds from this offering.

The actual number of Shares we will issue in this offering, at any one time or in total, is uncertain.

Subject to certain limitations set forth in the Sales Agreement with the Agent and compliance with applicable law, we have the discretion to deliver placement notices to the Agent at any time throughout the term of the Sales Agreement. The number of Shares that are sold by the Agent after we deliver a placement notice will fluctuate based on the market price of the Shares during the sales period and the limits we set with the Agent.

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The common stock offered hereby will be sold in “at the market offerings,” and investors who buy shares at different times will likely pay different prices.

Investors who purchase shares in this offering at different times will likely pay different prices, and so they may experience different levels of dilution and different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices, and numbers of shares sold in this offering. In addition, there is no minimum or maximum sales price for shares to be sold in this offering. Investors may experience a decline in the value of the shares they purchase in this offering as a result of sales made at prices lower than the prices they paid.

You may experience immediate and substantial dilution in the net tangible book value per share of the common stock you purchase.

The offering price per share in this offering may exceed the net tangible book value per share of our common stock outstanding prior to this offering. Assuming that an aggregate of 15,290,520 shares of our common stock are sold at a price of $3.27 per share pursuant to this prospectus supplement, which was the last reported sale price of our common stock on the Nasdaq Capital Market on September 22, 2021, for aggregate gross proceeds of $50.0 million (of which $41.6 million remains available), after deducting commissions and estimated aggregate offering expenses payable by us, you would experience immediate dilution of $0.62 per share, representing the difference between our as adjusted net tangible book value per share as of June 30, 2021 after giving effect to this offering the shares previously issued and sold under the Prior Prospectus Supplement, the Reverse Stock Split and the assumed offering price.

You may experience future dilution as a result of future equity offerings.

In order to raise additional capital, we may in the future offer additional shares of our common stock or other securities convertible into or exchangeable for our common stock at prices that may not be the same as the price per share in this offering. We may sell shares or other securities in any other offering at a price per share that is less than the price per share paid by investors in this offering, and investors purchasing shares or other securities in the future could have rights superior to existing stockholders. The price per share at which we sell additional shares of our Class A common stock, or securities convertible or exchangeable into common stock, in future transactions may be higher or lower than the price per share paid by investors in this offering.

In addition, the sale of shares in this offering and any future sales of a substantial number of shares of our common stock in the public market, or the perception that such sales may occur, could adversely affect the price of our common stock. We cannot predict the effect, if any, that market sales of those shares of common stock, or the perception that those shares may be sold, will have on the market price of our common stock.

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USE OF PROCEEDS

We intend to use the net proceeds from the sales of Shares offered hereby to fund ongoing operations. Pending such use, we may invest the net proceeds in short-term interest-bearing accounts, securities or similar investments. The amount of net proceeds we will receive from this offering, if any, will depend upon the actual number of Shares sold and the market price at which such Shares are sold. Further, because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and net proceeds to us, if any, are not determinable at this time.

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DILUTION

If you invest in our common stock in this offering, your ownership interest will be diluted to the extent of the difference between the price per share you pay in this offering and the as adjusted net tangible book value per share of our common stock immediately after this offering.

Our historical net tangible book value is the amount of our total tangible assets less our liabilities. Our historical net tangible book value per share is our historical net tangible book value divided by the number of shares of common stock outstanding as of June 30, 2021. Our historical net tangible book value as of June 30, 2021 was approximately $10.30 million or $1.53 per share of common stock.

After giving effect to the sale by us of shares of our common stock in the aggregate amount of $50.0 million (of which $41.6 million remains available), at an assumed offering price of $3.27 per share (the last reported sale price of our common stock on the Nasdaq Capital Market on September 22, 2021), and the Reverse Stock Split, and after deducting estimated commissions and estimated offering expenses payable by us, our as adjusted net tangible book value as of June 30, 2021 would have been $58.30 million, or $2.65 per share. This amount represents an immediate increase in as adjusted net tangible book value of $1.12 per share to our existing stockholders and an immediate dilution of $0.62 in as adjusted net tangible book value to new investors purchasing shares of common stock in this offering at the assumed offering price. Dilution per share to new investors is determined by subtracting as adjusted net tangible book value per share after this offering from the assumed offering price per share paid by new investors.

The following table illustrates this dilution on a per share basis. The as adjusted information is illustrative only and will adjust based on the actual price to the public, the actual number of shares sold and other terms of the offering determined at the time shares of our common stock are sold pursuant to this prospectus supplement. The as adjusted information assumes that all of our common stock in the aggregate amount of $50.0 million (of which $41.6 million remains available) is sold at the offering price of $3.27 per share, the last reported sale price of our common stock on the Nasdaq Capital Market on September 22, 2021. The shares sold in this offering, if any, will be sold from time to time at various prices.

Assumed public offering price per share			$	3.27
Historical net tangible book value per share as of June 30, 2021	$	1.53
Increase in net tangible book value per share attributable to this offering	$	1.12
As adjusted net tangible book value per share after this offering			$	2.65
Dilution per share to investors purchasing in this offering			$	0.62

The shares of common stock sold in this offering, if any, will be sold from time to time at various prices. An increase of $0.50 per share in the price at which the shares are sold from the assumed offering price of $3.77 per share shown in the table above, assuming all shares of common stock in the aggregate amount of $50.0 million (of which $41.6 million remains available) is sold at that price, would increase our as adjusted net tangible book value per share after the offering by $1.39 per share to $2.92 per share, after deducting commissions and estimated offering expenses payable by us. A decrease of $0.50 per share in the price at which the shares of common stock are sold from the assumed offering price of $2.77 per share shown in the table above, assuming all shares of common stock in the aggregate amount of $50.0 million (of which $41.6 million remains available) is sold at that price, would increase our as adjusted net tangible book value per share after the offering by $0.82 per share to $2.35 per share, after deducting commissions and estimated offering expenses payable by us. This information is supplied for illustrative purposes only.

The number of shares of our common stock to be outstanding after this offering is based on 6,695,331 shares of common stock outstanding as of June 30, 2021. All share numbers and per share amounts in this prospectus supplement have been retroactively adjusted to reflect the Reverse Stock Split.

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Furthermore, we may choose to raise additional capital through the sale of equity or convertible securities due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that we issue additional shares of common stock or other equity or convertible securities in the future, there will be further dilution to investors purchasing in this offering.

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DESCRIPTION OF OUR CAPITAL STOCK

The following is a description of our common stock, which is the only security of the Company registered pursuant to Section 12 of the Securities Exchange Act of 1934, as amended. The following summary description is based on the provisions of our Amended and Restated Certificate of Incorporation (the “Certificate of Incorporation”), our Amended and Restated Bylaws, (the “Bylaws”), and the applicable provisions of the Delaware General Corporation Law (the “DGCL”). This information may not be complete in all respects and is qualified entirely by reference to the provisions of our Certificate of Incorporation, our Bylaws and the DGCL. Our Certificate of Incorporation, as amended by the Certificate of Amendment filed as Exhibit 3.1 to the Form 8-K filed on September 15, 2021, and our Bylaws are filed as exhibits to our Annual Report on Form 10-K for the year ended December 31, 2020, as amended.

General

Our authorized capital stock consists of 100,000,000 shares of common stock, and 5,000,000 shares of undesignated preferred stock, $0.001 par value per share.

Common Stock

Dividend Rights

Subject to preferences that may apply to shares of preferred stock outstanding at the time, the holders of outstanding shares of our common stock are entitled to receive dividends out of funds legally available at the times and in the amounts that our board of directors may determine.

Voting Rights

Each holder of our common stock is entitled to one vote for each share of common stock held on all matters submitted to a vote of stockholders. Cumulative voting for the election of directors is not provided for in our certificate of incorporation, which means that the holders of a majority of our shares of common stock voted can elect all of the directors then standing for election.

Preemptive or Similar Rights

Our common stock is not entitled to preemptive rights and is not subject to conversion or redemption. The rights of the holders of our common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of our Preferred Stock that our board of directors may designate and issue in the future.

Liquidation Rights

Upon our liquidation, dissolution, or winding-up, the assets legally available for distribution to our stockholders would be distributable ratably among the holders of our common stock and any participating preferred stock outstanding at that time after payment of liquidation preferences, if any, on any outstanding shares of preferred stock and payment of other claims of creditors.

Preferred Stock

Our board of directors is authorized, subject to limitations prescribed by Delaware law, to issue up to 5,000,000 shares of our preferred stock in one or more series, to establish from time to time the number of shares to be included in each series, to fix the designation, powers, preferences, and rights of the shares of each series and any of its qualifications, limitations, or restrictions, in each case without further action by our stockholders. Our board of directors can also increase or decrease the number of shares of any series of preferred stock, but not

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below the number of shares of that series then outstanding, unless approved by the affirmative vote of the holders of a majority of our capital stock entitled to vote, or such other vote as may be required by the certificate of designation establishing the series. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of the common stock.

The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring, or preventing a change in our control and might adversely affect the market price of our common stock and the voting and other rights of the holders of our common stock.

Anti-Takeover Effects of the Certificate of Incorporation and Bylaws and Delaware Law

Our Certificate of Incorporation and Bylaws contain certain provisions that could have the effect of delaying, deterring, or preventing another party from acquiring control of our company. These provisions and certain provisions of the DGCL, which are summarized below, may discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed, in part, to encourage persons seeking to acquire control of our company to negotiate first with our board of directors.

Undesignated Preferred Stock

As discussed above, our board of directors have the ability to issue preferred stock with voting or other rights or preferences that could impede the success of any attempt to acquire control of our company. These and other provisions may have the effect of deterring hostile takeovers or delaying changes in control or management of our company.

Limits on Ability of Stockholders to Act by Written Consent or Call a Special Meeting

Our Certificate of Incorporation provides that our stockholders may not act by written consent, which may lengthen the amount of time required to take stockholder actions. As a result, a holder controlling a majority of our capital stock would not be able to amend our Bylaws or remove directors without holding a meeting of our stockholders called in accordance with our Bylaws.

In addition, our Bylaws provide that special meetings of the stockholders may be called only by the chairperson of our board, our Chief Executive Officer, or our board of directors. Stockholders may not call a special meeting, which may delay the ability of our stockholders to force consideration of a proposal or for holders controlling a majority of our capital stock to take any action, including the removal of directors.

Requirements for Advance Notification of Stockholder Nominations and Proposals

Our Bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of our board of directors or a committee of our board of directors. These provisions may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed. These provisions may also discourage or deter a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to obtain control of our company.

No Cumulative Voting

Our Certificate of Incorporation and Bylaws do not permit cumulative voting in the election of directors. Cumulative voting allows a stockholder to vote a portion or all of the stockholder’s shares for one or more candidates for seats on the board of directors. Without cumulative voting, a minority stockholder may not be able

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to gain as many seats on our board of directors as the stockholder would be able to gain if cumulative voting were permitted. The absence of cumulative voting makes it more difficult for a minority stockholder to gain a seat on our board of directors to influence our board’s decision regarding a takeover or otherwise.

Amendment of Certificate of Incorporation and Bylaws Provisions

The amendment of the above provisions of our Certificate of Incorporation and Bylaws requires approval by holders of at least two-thirds of our outstanding capital stock entitled to vote generally in the election of directors.

Delaware Anti-Takeover Statute

We are subject to the provisions of Section 203 of the DGCL (“Section 203”) regulating corporate takeovers. In general, Section 203 prohibits a publicly held Delaware corporation from engaging, under certain circumstances, in a business combination with an interested stockholder for a period of three years following the date the person became an interested stockholder unless:

• prior to the date of the transaction, our board of directors approved either the business combination or the transaction that resulted in the stockholder becoming an interested stockholder;

• upon completion of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, calculated as provided under Section 203; or

• at or subsequent to the date of the transaction, the business combination is approved by our board of directors and authorized at an annual or special meeting of stockholders, and not by written consent, by the affirmative vote of at least two-thirds of the outstanding voting stock which is not owned by the interested stockholder.

Generally, a business combination includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. An interested stockholder is a person that, together with affiliates and associates, owns or, within three years prior to the determination of interested stockholder status, did own 15% or more of a corporation’s outstanding voting stock. The existence of this provision may have an anti-takeover effect with respect to transactions our board of directors does not approve in advance. We also anticipate that Section 203 may also discourage attempts that might result in a premium over the market price for the shares of Common Stock held by stockholders.

The provisions of the DGCL and the provisions of our Certificate of Incorporation and Bylaws could have the effect of discouraging others from attempting hostile takeovers and, as a consequence, might also inhibit temporary fluctuations in the market price of our common stock that often result from actual or rumored hostile takeover attempts. These provisions might also have the effect of preventing changes in our management. It is possible that these provisions could make it more difficult to accomplish transactions that stockholders might otherwise deem to be in their best interests.

Choice of Forum

Our Certificate of Incorporation provides that the Court of Chancery of the State of Delaware (or, if and only if the Court of Chancery of the State of Delaware lacks subject matter jurisdiction, any state court located within the State of Delaware or, if and only if all such state courts lack subject matter jurisdiction, the federal district court for the District of Delaware) shall be the exclusive forum for the following types of actions or proceedings under Delaware statutory or common law: (i) any derivative action or proceeding brought on our behalf; (ii) any action asserting a breach of fiduciary duty owed by any director, officer or other employee to us or our stockholders; (iii) any action asserting a claim against us or any director or officer or other employee

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arising pursuant to the DGCL, our Certificate of Incorporation or Bylaws; (iv) any action or proceeding to interpret, apply, enforce or determine the validity of the Certificate of Incorporation or the Bylaws; (v) any action or proceeding as to which the DGCL confers jurisdiction to the Court of Chancery of the State of Delaware; or (vi) any action asserting a claim against us or any director or officer or other employee that is governed by the internal affairs doctrine, in all cases to the fullest extent permitted by law and subject to the court’s having personal jurisdiction over the indispensable parties named as defendants. This provision would not apply to claims brought to enforce a duty or liability created by the Exchange Act or any other claim for which the federal courts have exclusive jurisdiction. Our Certificate of Incorporation further provides that the federal district courts of the United States of America will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act of 1933, as amended (“Securities Act”).

Registration Rights

Certain holders of our common stock are entitled to rights with respect to the registration of their shares under the Securities Act. These registration rights are contained in our Amended and Restated Investors’ Rights Agreement (“IRA”), dated as of November 12, 2012, which is filed as an exhibit to our Annual Report on Form 10-K for the year ended December 31, 2020, as amended. The IRA provides that certain holders of our common stock have rights which require us to file registration statements covering the sale of their shares or to include their shares in registration statements that we may file for ourselves or other stockholders. The registration of shares of our common stock by the exercise of registration rights described would enable the holders to sell these shares without restriction under the Securities Act, when the applicable registration statement is declared effective. The registration rights under the IRA will expire five years following the completion of our initial public offering (May 14, 2024) or, with respect to any particular stockholder, when such stockholder holds 1% or less of our common stock and is able to sell all of its shares pursuant to Rule 144 of the Securities Act during any three month period.

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MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERS OF OUR COMMON STOCK

The following summary describes the material U.S. federal income tax consequences of the acquisition, ownership and disposition of our common stock acquired in this offering by Non-U.S. Holders (as defined below). This discussion is not a complete analysis of all potential U.S. federal income tax consequences relating thereto, and does not deal with state, local and non-U.S. tax consequences that may be relevant to Non-U.S. Holders in light of their particular circumstances, nor does it address U.S. federal tax consequences (such as gift and estate taxes) other than income taxes. Special rules different from those described below may apply to certain Non-U.S. Holders that are subject to special treatment under the Code, such as financial institutions, insurance companies, tax-exempt organizations, broker-dealers and traders in securities, U.S. expatriates, “controlled foreign corporations,” “passive foreign investment companies,” corporations that accumulate earnings to avoid U.S. federal income tax, corporations organized outside of the United States, any state thereof and the District of Columbia that are nonetheless treated as U.S. taxpayers for U.S. federal income tax purposes, persons that hold our common stock as part of a “straddle,” “hedge,” “conversion transaction,” “synthetic security” or integrated investment or other risk reduction strategy, persons who acquire our common stock through the exercise of an option or otherwise as compensation, persons subject to the alternative minimum tax or federal Medicare contribution tax on net investment income, persons subject to special tax accounting rules under Section 451(b) of the Code, “qualified foreign pension funds” as defined in Section 897(l)(2) of the Code and entities all of the interests of which are held by qualified foreign pension funds, partnerships and other pass-through entities or arrangements, and investors in such pass-through entities or arrangements. Such Non-U.S. Holders are urged to consult their own tax advisors to determine the U.S. federal, state, local and other tax consequences that may be relevant to them. Furthermore, the discussion below is based upon the provisions of the Code, Treasury Regulations thereunder, and rulings and judicial decisions with respect thereto as of the date hereof, and such authorities may be repealed, revoked or modified, perhaps retroactively, so as to result in U.S. federal income tax consequences different from those discussed below. We have not requested a ruling from the U.S. Internal Revenue Service, or the IRS, with respect to the statements made and the conclusions reached in the following summary, and there can be no assurance that the IRS will agree with such statements and conclusions. This discussion assumes that the Non-U.S. Holder holds our common stock as a “capital asset” within the meaning of Section 1221 of the Code (generally, property held for investment).

This discussion is for informational purposes only and is not tax advice. Persons considering the purchase of our common stock pursuant to this offering should consult their own tax advisors concerning the U.S. federal income, estate and other tax consequences of acquiring, owning and disposing of our common stock in light of their particular situations as well as any consequences arising under the laws of any other taxing jurisdiction, including any state, local or foreign tax consequences.

For the purposes of this discussion, a “Non-U.S. Holder” is, for U.S. federal income tax purposes, a beneficial owner of common stock that is neither a U.S. Holder, nor a partnership or other entity or arrangement treated as a partnership for U.S. federal income tax purposes regardless of its place of organization or formation. A “U.S. Holder” means a beneficial owner of common stock that is for U.S. federal income tax purposes any of the following:

• an individual who is a citizen or resident of the United States;

• a corporation or other entity treated as a corporation for U.S. federal income tax purposes created or organized in or under the laws of the United States, any state thereof or the District of Columbia;

• an estate the income of which is subject to U.S. federal income taxation regardless of its source; or

• a trust if it (1) is subject to the primary supervision of a court within the United States and one or more U.S. persons have the authority to control all substantial decisions of the trust or (2) has a valid election in effect under applicable U.S. Treasury Regulations to be treated as a U.S. person.

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Distributions

Distributions, if any, made on our common stock to a Non-U.S. Holder to the extent made out of our current or accumulated earnings and profits (as determined under U.S. federal income tax principles) generally will constitute dividends for U.S. tax purposes and will be subject to withholding tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty, subject to the discussions below regarding effectively connected income, backup withholding and foreign accounts. To obtain a reduced rate of withholding under a treaty, a Non-U.S. Holder generally will be required to provide us with a properly executed IRS Form W-8BEN (in the case of individuals) or IRS Form W-8BEN-E (in the case of entities), or other appropriate form, certifying the Non-U.S. Holder’s entitlement to benefits under that treaty. This certification must be provided to us or our paying agent prior to the payment of dividends and must be updated periodically. In the case of a Non-U.S. Holder that is an entity, Treasury Regulations and the relevant tax treaty provide rules to determine whether, for purposes of determining the applicability of a tax treaty, dividends will be treated as paid to the entity or to those holding an interest in that entity. If a Non-U.S. Holder holds stock through a financial institution or other agent acting on the Non-U.S. Holder’s behalf, the Non-U.S. Holder will be required to provide appropriate documentation to such agent. The Non-U.S. Holder’s agent will then be required to provide certification to us or our paying agent, either directly or through other intermediaries. If a Non-U.S. Holder is eligible for a reduced rate of U.S. federal withholding tax under an income tax treaty and does not timely file the required certification, the Non-U.S. Holder may be able to obtain a refund or credit of any excess amounts withheld by timely filing an appropriate claim for a refund with the IRS.

We generally are not required to withhold tax on dividends paid to a Non-U.S. Holder that are effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States (and, if required by an applicable income tax treaty, are attributable to a permanent establishment or fixed base that such Non-U.S. Holder maintains in the United States) if a properly executed IRS Form W-8ECI, stating that the dividends are so connected, is furnished to us (or, if stock is held through a financial institution or other agent, to such agent). In general, such effectively connected dividends will be subject to U.S. federal income tax, on a net-income basis at the regular rates applicable to U.S. residents. A corporate Non-U.S. Holder receiving effectively connected dividends may also be subject to an additional “branch profits tax,” which is imposed, under certain circumstances, at a rate of 30% (or such lower rate as may be specified by an applicable income tax treaty) on the corporate Non-U.S. Holder’s effectively connected earnings and profits, subject to certain adjustments. Non-U.S. Holders should consult their tax advisors regarding any applicable income tax treaties that may provide for different rules.

To the extent distributions on our common stock, if any, exceed our current and accumulated earnings and profits, they will first reduce the Non-U.S. Holder’s adjusted basis in our common stock, but not below zero, and then will be treated as gain to the extent of any excess amount distributed and taxed in the same manner as gain realized from a sale or other disposition of common stock as described in the next section.

Gain on Disposition of Our Common Stock

Subject to the discussions below regarding backup withholding and foreign accounts, a Non-U.S. Holder generally will not be subject to U.S. federal income tax with respect to gain realized on a sale or other disposition of our common stock unless (a) the gain is effectively connected with a trade or business of such Non-U.S. Holder in the United States (and, if required by an applicable income tax treaty, is attributable to a permanent establishment or fixed base that such holder maintains in the United States), (b) the Non-U.S. Holder is a nonresident alien individual and is present in the United States for 183 or more days in the taxable year of the disposition and certain other conditions are met or (c) we are or have been a “United States real property holding corporation” within the meaning of Code Section 897(c)(2) at any time within the shorter of the five-year period preceding such disposition or such Non-U.S. Holder’s holding period. In general, we would be a United States real property holding corporation if our worldwide real estate and certain other interests in U.S. real estate comprise (by fair market value) at least half of our business assets. We believe that we have not been and we are not, and do not anticipate becoming, a United States real property holding corporation.

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Even if we are treated as a United States real property holding corporation, gain realized by a Non-U.S. Holder on a disposition of our common stock will not be subject to U.S. federal income tax so long as (1) the Non-U.S. Holder owned, directly, indirectly and constructively, no more than 5% of our common stock at all times within the shorter of (i) the five-year period preceding the disposition or (ii) the Non-U.S. Holder holding period and (2) our common stock is regularly traded on an established securities market. There can be no assurance that our common stock will continue to qualify as regularly traded on an established securities market. If any gain on a Non-U.S. Holder’s disposition is taxable because we are a United States real property holding corporation and such Non-U.S. Holder’s ownership of our common stock exceeds 5%, the Non-U.S. Holder will be taxed on such disposition generally in the manner as gain that is effectively connected with the conduct of a U.S. trade or business (subject to the provisions under an applicable income tax treaty), except that the branch profits tax generally will not apply to corporate Non-U.S. Holders.

A Non-U.S. Holder described in (a) above will be required to pay tax on the net gain derived from the sale at regular U.S. federal income tax rates, and corporate Non-U.S. Holders described in (a) above may be subject to the additional branch profits tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. Gain described in (b) above will be subject to U.S. federal income tax at a flat 30% rate or such lower rate as may be specified by an applicable income tax treaty, which gain may be offset by certain U.S.-source capital losses (even though the Non-U.S. Holder is not considered a resident of the United States) provided that the Non-U.S. Holder has timely filed U.S. federal income tax returns with respect to such losses.

Information Reporting Requirements and Backup Withholding

Generally, we must report information to the IRS with respect to any dividends we pay on our common stock (even if the payments are exempt from withholding), including the amount of any such dividends, the name and address of the recipient and the amount, if any, of tax withheld. A similar report is sent to the Non-U.S. Holder to whom any such dividends are paid. Pursuant to tax treaties or certain other agreements, the IRS may make its reports available to tax authorities in the recipient’s country of residence.

Dividends paid by us (or our paying agents) to a Non-U.S. Holder may also be subject to U.S. backup withholding (currently at a rate of 24%). U.S. backup withholding generally will not apply to a Non-U.S. Holder who provides a properly executed IRS Form W-8BEN, IRS Form W-8BEN-E or IRS Form W-ECI (as applicable), or otherwise establishes an exemption. Notwithstanding the foregoing, backup withholding may apply if the payer has actual knowledge, or reason to know, that the holder is a U.S. person who is not an exempt recipient.

U.S. information reporting and backup withholding requirements generally will apply to the proceeds of a disposition of our common stock effected by or through a U.S. office of any broker, U.S. or foreign, except that information reporting and such requirements may be avoided if the Non-U.S. Holder provides a properly executed IRS Form W-8BEN or IRS Form W-8BEN-E or otherwise meets documentary evidence requirements for establishing non-U.S. person status or otherwise establishes an exemption. Generally, U.S. information reporting and backup withholding requirements will not apply to a payment of disposition proceeds to a Non-U.S. Holder where the transaction is effected outside the United States through a non-U.S. office of a non-U.S. broker. Information reporting and backup withholding requirements may, however, apply to a payment of disposition proceeds if the broker has actual knowledge, or reason to know, that the holder is, in fact, a U.S. person. For information reporting purposes, certain brokers with substantial U.S. ownership or operations will generally be treated in a manner similar to U.S. brokers.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be credited against the tax liability of persons subject to backup withholding, provided that the required information is timely furnished to the IRS.

S-23

Foreign Accounts

Sections 1471 through 1474 of the Code (commonly referred to as FATCA) impose a U.S. federal withholding tax of 30% on certain payments, including dividends paid on, and, subject to the discussion below, the gross proceeds of a disposition of, our common stock paid to a foreign financial institution (as specifically defined by applicable rules) unless such institution enters into an agreement with the U.S. government to withhold on certain payments and to collect and provide to the U.S. tax authorities substantial information regarding U.S. account holders of such institution (which includes certain equity holders of such institution, as well as certain account holders that are foreign entities with U.S. owners). FATCA also generally imposes a federal withholding tax of 30% on certain payments, including dividends paid on, and, subject to the discussion below, the gross proceeds of a disposition of, our common stock to a non-financial foreign entity unless such entity provides the withholding agent with either a certification that it does not have any substantial direct or indirect U.S. owners or provides information regarding substantial direct and indirect U.S. owners of the entity. An intergovernmental agreement between the United States and an applicable foreign country may modify those requirements. The withholding tax described above will not apply if the foreign financial institution or non-financial foreign entity otherwise qualifies for an exemption from the rules.

The U.S. Treasury Department released proposed regulations which, if finalized in their present form, would eliminate the federal withholding tax of 30% applicable to the gross proceeds of a disposition of our common stock. In its preamble to such proposed regulations, the U.S. Treasury Department stated that taxpayers may generally rely on the proposed regulations until final regulations are issued. Non-U.S. Holders are encouraged to consult with their own tax advisors regarding the possible implications of FATCA on their investment in our common stock.

EACH PROSPECTIVE INVESTOR SHOULD CONSULT ITS OWN TAX ADVISOR REGARDING THE TAX CONSEQUENCES OF PURCHASING, HOLDING AND DISPOSING OF OUR COMMON STOCK, INCLUDING THE CONSEQUENCES OF ANY RECENT OR PROPOSED CHANGE IN APPLICABLE LAW.

S-24

PLAN OF DISTRIBUTION

We have entered into an At Market Issuance Sales Agreement, dated September 23, 2021 (“Sales Agreement”), with B. Riley Securities, or the Agent, under which we may issue and sell our common stock from time to time through or to the Agent acting as sales agent or principal, subject to certain limitations, including the dollar value of securities registered and remaining available for sale under the registration statement to which this offering relates.

Sales of our common stock, if any, under this prospectus supplement and the accompanying prospectus may be made by any method that is deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act. We may instruct the Agent not to sell common stock if the sales cannot be effected at or above the price designated by us from time to time. We or the Agent may suspend the offering of common stock upon notice and subject to other conditions.

The Agent will offer our common stock, subject to the terms and conditions of the Sales Agreement, as agreed upon by us and the Agent. Each time we wish to issue and sell common stock under the Sales Agreement, we will notify the Agent of the number or dollar value of shares proposed to be issued, the dates on which such sales are requested to be made, any limitation on the number of shares that may be sold in any one trading day, any minimum price below which sales may not be made, and other sales parameters as we deem appropriate. Once we have so instructed the Agent, unless the Agent declines to accept the terms of the notice, the Agent has agreed to use its commercially reasonable efforts consistent with its normal trading and sales practices to sell such shares up to the amount specified on such terms. The obligation of the Agent under the Sales Agreement to sell our common stock is subject to a number of conditions that we must meet.

We will pay the Agent a commission for its services in acting as agent in the sale of our common stock. The Agent will be entitled to a commission equal to 3.0% of the gross proceeds from each sale of common stock under the Sales Agreement. In addition, we have agreed to reimburse the Agent for certain fees and disbursements to its legal counsel in connection with (i) entering into the transactions contemplated by the Sales Agreement in an amount not to exceed $50,000 in the aggregate, and (ii) ongoing diligence arising from the transactions contemplated by the Sales Agreement in an amount not to exceed $10,000 per year, provided that such fees shall only be incurred and payable in quarters during which sales are being made by the Agent pursuant to a placement notice.

We estimate that the total expenses for the offering, excluding compensation payable to the Agent under the terms of the Sales Agreement, will be approximately $500,000.

The amount of net proceeds we will receive from this offering, if any, will depend upon the actual number of shares of our common stock sold and the market price at which such shares are sold. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and net proceeds to us, if any, are not determinable at this time.

Settlement for sales of our common stock will generally occur on the second trading day following the date on which any sales are made, or on some other date that is agreed upon by us and the Agent in connection with a particular transaction, in return for payment of the net proceeds to us. There is no arrangement to place proceeds of the offering in escrow, trust or similar arrangement.

In connection with the sale of the common stock on our behalf, the Agent will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of the Agent will be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to the Agent with respect to certain civil liabilities, including liabilities under the Securities Act.

This offering of our common stock pursuant to the Sales Agreement will terminate upon the earlier of (i) the sale of all of our common stock provided for in this prospectus supplement, or (ii) termination of the Sales Agreement as provided therein.

S-25

Conflict of Interest

The Agent and its affiliates are currently providing, and may in the future provide, various investment banking and other financial services for us, for which services they have received and will continue to receive customary fees. In addition, in the ordinary course of their various business activities, the Agent and its affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments issued by us. The Agent or its affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments. To the extent required by Regulation M, the Agent will not engage in any market making activities involving our common stock while the offering is ongoing under this prospectus supplement.

S-26

LEGAL MATTERS

Certain legal matters will be passed upon for us by O’Melveny & Myers LLP, San Francisco, California, and for the Agent by Duane Morris LLP, New York, New York.

S-27

EXPERTS

The consolidated financial statements of Sonim Technologies, Inc. incorporated in this Prospectus Supplement by reference from Sonim Technologies, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2020 have been audited by Moss Adams LLP, an independent registered public accounting firm, as set forth in their report, which is incorporated by reference herein. Such consolidated financial statements have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.

S-28

INFORMATION INCORPORATED BY REFERENCE

This prospectus supplement and the accompanying prospectus are part of a registration statement that we have filed with the SEC. The SEC allows us to “incorporate by reference” the information that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus supplement and the accompanying prospectus from the date we file that document. Any documents filed by us under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act with the SEC (including those portions of our Definitive Proxy Statement on Schedule 14A, as filed with the SEC, specifically incorporated by reference in our Annual Report on Form 10-K or amendments thereto); after the date of this prospectus supplement and before the date that the offering of shares by means of this prospectus supplement and accompanying prospectus is terminated will automatically update and, where applicable, supersede any information contained or incorporated by reference in this prospectus supplement and accompanying prospectus. We incorporate by reference into this prospectus supplement and the accompanying prospectus the following documents or information filed with the SEC (other than, in each case, documents or information deemed to have been furnished and not filed in accordance with SEC rules):

• Our Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 18, 2021, as amended by Amendment No. 1 to our Annual Report on Form 10-K, as filed with the SEC on April 6, 2021 and Amendment No. 2 to our Annual Report on Form 10-K, as filed with the SEC on June 16, 2021;

• Our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021, filed with the SEC on May 11, 2021, as amended by Amendment No. 1 to our Quarterly Report on Form 10-Q, as filed with the SEC on June 16, 2021, and June  30, 2021, filed with the SEC on August 16, 2021;

• Our Current Reports on Form  8-K filed with the SEC on January 21,  2021, February 24, 2021, March 4,  2021 (with respect to Item 1.01 and Exhibit 10.1 of Item 9.01 only), April 21, 2021 (with respect to Item  5.02 only), April 28, 2021, June  1, 2021 (with respect to Item 5.02 and Exhibit 10.1 of Item 9.01 only), June  30, 2021, July  20, 2021 and September 15, 2021; and

• The description of our common stock contained in Exhibit 4.4 of our Annual Report on Form 10-K for the year ended December 31, 2020, including any amendments or reports filed for the purposes of updating this description.

We will provide without charge to each person, including any beneficial owner, to whom this prospectus supplement and the accompanying prospectus are delivered, upon his or her written or oral request, a copy of any or all documents referred to above that have been or may be incorporated by reference into this prospectus supplement and the accompanying prospectus, excluding exhibits to those documents unless they are specifically incorporated by reference into those documents. You may request those documents from us by contacting us at the following address:

Sonim Technologies, Inc.

6500 River Place Boulevard, Bldg. 7, S#250

Austin, Texas 78730

(650) 378-8100

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WHERE YOU CAN FIND MORE INFORMATION

We are currently subject to the information requirements of the Exchange Act, and in accordance therewith file periodic reports, proxy statements and other information with the SEC. Our filings with the SEC are available to the public from the SEC’s website at www.sec.gov. In addition, our common stock is listed on the Nasdaq Capital Market, and our reports and other information can be inspected at the offices of the Nasdaq Capital Market, 20 Broad Street, New York, New York 10005. We maintain a website at www.sonimtech.com. The information on our website is not part of or incorporated by reference in this prospectus supplement or the accompanying prospectus.

S-30

PROSPECTUS

Sonim Technologies, Inc.

$50,000,000

Common Stock

Preferred Stock

Debt Securities

Warrants

Rights

Units

From time to time, we may offer and sell up to $50,000,000 in aggregate of the securities described in this prospectus separately or together in any combination, in one or more classes or series, in amounts, at prices and on terms that we will determine at the time of the offering.

This prospectus provides a general description of the securities we may offer. We may provide specific terms of securities to be offered in one or more supplements to this prospectus. We may also provide a specific plan of distribution for any securities to be offered in a prospectus supplement. Prospectus supplements may also add, update or change information in this prospectus. You should carefully read this prospectus and the applicable prospectus supplement, together with any documents incorporated by reference herein, before you invest in our securities.

Our common stock is listed on The Nasdaq Capital Market under the symbol “SONM.” On March 17, 2021, the last reported sale price of our common stock was $0.99 per share. The applicable prospectus supplement will contain information, where applicable, as to the listing of any other securities covered by the prospectus supplement other than our common stock on the NYSE American or any other securities exchange.

Investing in any of our securities involves a high degree of risk. Please read carefully the section entitled “Risk Factors” on page 5 of this prospectus, the “Risk Factors” section contained in the applicable prospectus supplement and the information included and incorporated by reference in this prospectus. We are a “smaller reporting company” as defined under the U.S. federal securities laws and, as such, may elect to comply with certain reduced public company reporting requirements.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is April 12, 2021

TABLE OF CONTENTS

	Page
About This Prospectus		1
Where You Can Find More Information		2
Information We Incorporate By Reference		2
Special Note Regarding Forward-Looking Statements		3
Sonim Technologies, Inc.		4
Risk Factors		5
Use Of Proceeds		6
Description Of Debt Securities		7
Description Of Warrants		15
Description Of Rights		19
Description Of Units		20
Plan Of Distribution		21
Legal Matters		23
EXPERTS		23

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration or continuous offering process. Under this shelf registration process, we may, from time to time, sell any combination of the securities described in this prospectus in one or more offerings up to a total aggregate offering price of $50,000,000.

This prospectus provides a general description of the securities we may offer. We may provide specific terms of securities to be offered in one or more supplements to this prospectus. We may also provide a specific plan of distribution for any securities to be offered in a prospectus supplement. Prospectus supplements may also add, update or change information in this prospectus. If the information varies between this prospectus and the accompanying prospectus supplement, you should rely on the information in the accompanying prospectus supplement.

Before purchasing any securities, you should carefully read both this prospectus and any prospectus supplement, together with the additional information described under the heading “Information We Incorporate by Reference.” You should rely only on the information contained or incorporated by reference in this prospectus, any prospectus supplement and any free writing prospectus prepared by or on behalf of us or to which we have referred you. Neither we nor any underwriters have authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. You should assume that the information contained in this prospectus, any prospectus supplement or any free writing prospectus is accurate only as of the date on its respective cover, and that any information incorporated by reference is accurate only as of the date of the document incorporated by reference, unless we indicate otherwise. Our business, financial condition, results of operations and prospects may have changed since those dates. This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the heading “Where You Can Find More Information.”

This prospectus and any applicable prospectus supplement do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate. We are not making offers to sell common stock or any other securities described in this prospectus in any jurisdiction in which an offer or solicitation is not authorized or in which we are not qualified to do so or to anyone to whom it is unlawful to make an offer or solicitation.

Unless otherwise expressly indicated or the context otherwise requires, we use the terms “Sonim,” the “Company,” “we,” “us,” “our” or similar references to refer to Sonim Technologies, Inc. and its subsidiaries.

1

WHERE YOU CAN FIND MORE INFORMATION

We have filed our registration statement on Form S-3 with the SEC under the Securities Act of 1933, as amended, or the Securities Act. We also file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document that we file with the SEC, including the registration statement and the exhibits to the registration statement, at the SEC’s Public Reference Room located at 100 F Street, N.E., Washington D.C. 20549. You may obtain further information on the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0330. Our SEC filings are also available to the public at the SEC’s web site at www.sec.gov. These documents may also be accessed on our web site at www.sonimtech.com. Information contained on our web site is not incorporated by reference into this prospectus and you should not consider information contained on our web site to be part of this prospectus.

This prospectus and any prospectus supplement are part of a registration statement filed with the SEC and do not contain all of the information in the registration statement. The full registration statement may be obtained from the SEC or us as indicated above. Forms of any indenture or other documents establishing the terms of the offered securities are filed as exhibits to the registration statement or will be filed through an amendment to our registration statement on Form S-3 or under cover of a Current Report on Form 8-K and incorporated into this prospectus by reference.

INFORMATION WE INCORPORATE BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus the information we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Any statement contained herein or in a document incorporated or deemed to be incorporated by reference into this document will be deemed to be modified or superseded for purposes of the document to the extent that a statement contained in this document or any other subsequently filed document that is deemed to be incorporated by reference into this document modifies or supersedes the statement. We incorporate by reference in this prospectus the following information (other than, in each case, documents or information deemed to have been furnished and not filed in accordance with SEC rules):

• our Annual Report on Form 10-K for the fiscal year ended December 31, 2020 (filed with the SEC on March 18, 2021);

• our Current Reports on Form 8-K filed with the SEC on January 21, 2021, February 24, 2021, March 4, 2021 and March 11, 2021; and

• the description of our common stock contained in our registration statement on Form 8-A filed with the SEC on May 9, 2019, including any amendments or reports filed for the purposes of updating this description.

We also incorporate by reference each of the documents that we file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, on or after the date of this prospectus and prior to the termination of the offerings under this prospectus and any prospectus supplement. These documents include periodic reports, such as Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as proxy statements. We will not, however, incorporate by reference in this prospectus any documents or portions thereof that are not deemed “filed” with the SEC, including any information furnished pursuant to Item 2.02 or Item 7.01 of our Current Reports on Form 8-K after the date of this prospectus unless, and except to the extent, specified in such Current Reports.

We will provide to each person, including any beneficial owner, to whom a prospectus (or a notice of registration in lieu thereof) is delivered a copy of any of these filings (other than an exhibit to these filings, unless the exhibit is specifically incorporated by reference as an exhibit to this prospectus) at no cost, upon a request to us by writing or telephoning us at the following address and telephone number:

Sonim Technologies, Inc.

6836 Bee Cave Road, Bldg. 1, S#279

Austin, Texas 787

(650) 378-8100

2

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, including the documents incorporated by reference herein, may contain or incorporate “forward-looking statements” within the meaning of Section 21E of the Securities Exchange Act of 1934. We have based these forward-looking statements on our current expectations and projections about future events or future financial performance, which include successfully implementing our business strategy and realizing planned cost-savings, achieving profitability and continuing as a going concern developing and introducing new technologies, obtaining, maintaining and expanding market acceptance of the technologies we offer, and competition in our markets.

In some cases, these forward-looking statements can be identified by terminology such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “future,” “predict,” “potential,” “intend,” or “continue,” and similar expressions. These statements are based on the beliefs and assumptions of our management and on information currently available to our management. Our actual results, performance and achievements may differ materially from the results, performance and achievements expressed or implied in such forward-looking statements. For a discussion of some of the factors that might cause such a difference, see the “Risk Factors” contained in Part I, Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2020. Except as required by law, we specifically disclaim any obligation to update such forward-looking statements.

3

Sonim Technologies, Inc.

Sonim Technologies, Inc. was incorporated in the state of Delaware on August 5, 1999 and is headquartered in Austin, Texas. Unless otherwise indicated, the terms “we,” “us,” “our,” “Company” and “Sonim” refer to Sonim Technologies, Inc. and its wholly owned and consolidated subsidiaries.

We are a leading U.S. provider of ultra-rugged mobile phones and accessories designed specifically for task workers physically engaged in their work environments, often in mission-critical roles. We currently sell our ruggedized mobile phones and accessories to three of the four largest wireless carriers in the United States— AT&T, T-Mobile (referred to collectively as Sprint) and Verizon—as well as the three largest wireless carriers in Canada—Bell, Rogers and Telus Mobility. Our phones and accessories connect workers with voice, data and workflow applications in two end markets: industrial enterprise and public sector.

Task workers in these end markets have historically been limited to pen and paper and single-purpose electronic devices, such as barcode scanners, location-tracking devices and sensors, to accomplish specific tasks. These single-purpose devices have historically run on proprietary networks, such as Land Mobile Radio (LMR) networks that enable Push-to-Talk (PTT) services for voice communications. We provide Android-based devices that consolidate and integrate multiple functions into a single ruggedized solution running on commercial wireless networks at a total cost of ownership that we believe is significantly lower with improved productivity and safety of task workers.

Our solutions consist primarily of ultra-rugged mobile phones based on the Android platform which are capable of attaching to both public and private wireless networks, industrial-grade accessories that meet the requirements of specific applications, and software applications and cloud-based tools that provide management and deployment services to our customers. End customers of our solutions include construction, energy and utility, hospitality, logistics, manufacturing, public sector and transportation entities that primarily purchase our devices and accessories through their wireless carriers. The key attributes of our solutions are specifically tailored for the needs of our end users, including impact resistance, waterproof and dustproof construction, extended battery life and extra loud audio, supported by a three-year comprehensive warranty. All of our devices run on the Android operating system, providing a familiar and intuitive user interface, and our smartphones have access to a library of millions of applications available through the Google Play Store. We have also implemented dozens of application programming interfaces, or APIs, specific to our mobile phones and have partnered with third-party application developers to create a purpose-built experience for our end users using these applications on our mobile phones.

We currently have stocked product with three of the four largest U.S. wireless carriers: AT&T, T-Mobile (which acquired Sprint in 2020) and Verizon, meaning that these carriers test and certify our mobile phones on their networks and maintain inventory in their warehouses that they then sell through their enterprise and retail sales teams to end customers, often on a subsidized or financed basis. Our full product portfolio has been stocked with the three largest Canadian wireless carriers since 2015. In 2020, we sold approximately 33,000 mobile phones in Canada and 205,000 in the United States (which markets include rugged feature phones, smart consumer rugged phones, smart ultra-rugged phones and life-proofed smart phones).

We enter into master sales arrangements with carriers (including channel partners contributing over 90% of our total revenues for the year ended December 31, 2020) under which our partners purchase our solutions for distribution on a purchase order basis. Under these arrangements, we and the channel partners determine sales channel distribution in connection with pricing (including any discounts and price protection) and market positioning of each particular mobile phone product. We also offer our channel partners channel marketing and other promotional incentives, such as sales volume incentives, in exchange for retail price reductions. We may also offer NRE services in the form of third-party design services relating to the design of materials and software licenses used in the manufacturing of our products.

4

RISK FACTORS

Investing in our securities involves a high degree of risk. Before making an investment decision, you should carefully consider any risk factors set forth in the applicable prospectus supplement and the documents incorporated by reference in this prospectus, including the factors discussed under the heading “Risk Factors” in our most recent Annual Report on Form 10-K and each subsequently filed Quarterly Report on Form 10-Q and any risk factors set forth in our other filings with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange. See “Where You Can Find More Information” and “Information We Incorporate By Reference.” Each of the risks described in these documents could materially and adversely affect our business, financial condition, results of operations and prospects, and could result in a partial or complete loss of your investment. Additional risks and uncertainties not presently known to us, or that we currently deem immaterial, may also adversely affect our business. In addition, past financial performance may not be a reliable indicator of future performance and historical trends should not be used to anticipate results or trends in future periods.

5

USE OF PROCEEDS

We will retain broad discretion over the use of the net proceeds from the sale of the securities offered hereby. Unless otherwise specified in any prospectus supplement, we currently intend to use the net proceeds from the sale of our securities offered under this prospectus for working capital and general corporate purposes including, but not limited to, capital expenditures, working capital, repayment of indebtedness, potential acquisitions and other business opportunities. Pending any specific application, we may initially invest funds in short-term marketable securities or apply them to the reduction of indebtedness.

6

DESCRIPTION OF DEBT SECURITIES

The following description, together with the additional information we include in any applicable prospectus supplement, summarizes certain general terms and provisions of the debt securities that we may offer in one or more series under this prospectus. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. We will also indicate in the supplement to what extent the general terms and provisions described in this prospectus apply to a particular series of debt securities.

We may issue debt securities either separately, or together with, or upon the conversion or exercise of or in exchange for, other securities described in this prospectus. Debt securities may be our senior, senior subordinated or subordinated obligations and, unless otherwise specified in a supplement to this prospectus, the debt securities will be our direct, unsecured obligations.

We will issue the debt securities under the indenture that we will enter into with a national banking association or other eligible party, as trustee. The indenture will be qualified under the Trust Indenture Act of 1939, as amended, or the Trust Indenture Act. We have filed the form of indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The following summary of material provisions of the debt securities and the indenture is subject to, and qualified in its entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. The summary is not complete. The form of the indenture has been filed as an exhibit to the registration statement and you should read the indenture for provisions that may be important to you. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the debt securities that we may offer under this prospectus, as well as the complete indenture that contains the terms of the debt securities.

General

We can issue an unlimited amount of debt securities under the indenture that may be in one or more series with the same or various maturities, at par, at a premium, or at a discount. The terms of each series of debt securities will be established by or pursuant to a resolution of our board of directors and set forth in an officer’s certificate or a supplemental indenture. The particular terms of each series of debt securities will be described in a prospectus supplement relating to such series (including any pricing supplement or term sheet), including the following terms, if applicable:

• the title and ranking of the debt securities (including the terms of any subordination provisions);

• the price or prices (expressed as a percentage of the principal amount) at which we will sell the debt securities;

• the aggregate principal amount of the debt securities being offered and any limit on the aggregate principal amount of such series of debt securities;

• whether any of our direct or indirect subsidiaries will guarantee the debt securities, including the terms of subordination, if any, of such guarantees;

• the date or dates on which the principal of the securities of the series is payable;

• the interest rate, if any, and the method for calculating the interest rate;

• the dates from which interest will accrue, the interest payment dates and the record dates for the interest payments;

• the place or places where principal of, and any interest on, the debt securities will be payable (and the method of such payment), where the securities of such series may be surrendered for registration of transfer or exchange, and where notices and demands to us in respect of the debt securities may be delivered;

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• any mandatory or optional redemption terms;

• any obligation we have to redeem or purchase the debt securities pursuant to any sinking fund or analogous provisions or at the option of a holder of debt securities and the period or periods within which, the price or prices at which and the terms and conditions upon which securities of the series shall be redeemed or purchased, in whole or in part, pursuant to such obligation;

• any dates, if any, on which and the price or prices at which we will repurchase debt securities at the option of the holders of debt securities and other detailed terms and provisions of such repurchase obligations;

• the denominations in which the debt securities will be issued;

• whether the debt securities will be issued in the form of certificated debt securities or global debt securities;

• the currency of denomination of the debt securities, which may be U.S. dollars or any foreign currency, and if such currency of denomination is a composite currency, the agency or organization, if any, responsible for overseeing such composite currency;

• the designation of the currency, currencies or currency units in which payment of the principal of, and any interest on, the debt securities will be made;

• if payments of principal of, any interest on, the debt securities will be made in one or more currencies or currency units other than that or those in which the debt securities are denominated, the manner in which the exchange rate with respect to such payments will be determined;

• the manner in which the amounts of payment of principal of, or any interest on, the debt securities will be determined, if these amounts may be determined by reference to an index based on a currency or currencies or by reference to a commodity, commodity index, stock exchange index or financial index;

• any provisions relating to any security provided for the debt securities;

• any addition to, deletion of or change in the events of default described in this prospectus or in the indenture with respect to the debt securities and any change in the acceleration provisions described in this prospectus or in the indenture with respect to the debt securities;

• any addition to, deletion of or change in the covenants described in this prospectus or in the indenture with respect to the debt securities;

• any depositaries, interest rate calculation agents, exchange rate calculation agents or other agents appointed with respect to the debt securities;

• the provisions, if any, relating to conversion or exchange of any series of debt securities, including if applicable, the conversion or exchange price and period, the securities or other property into which the debt securities will be convertible, provisions as to whether conversion or exchange will be mandatory, at the option of the holders thereof or at our option, the events requiring an adjustment of the conversion price or exchange price and provisions affecting conversion or exchange if such series of debt securities are redeemed; and

• any other terms of the series of debt securities that may supplement, modify or delete any provision of the indenture as it applies to that series, including any terms that may be required under applicable law or regulations or advisable in connection with the marketing of the debt securities.

We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon maturity or a declaration of acceleration of their maturity following an event of default pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

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If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and any premium and interest on any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Transfer and Exchange

Each debt security will be represented by either one or more global securities registered in the name of The Depository Trust Company, or the depositary, or a nominee of the depositary (we will refer to any such debt security as a “global debt security”), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificate as a “certificated debt security”) as set forth in the applicable prospectus supplement. Except as set forth below, global debt securities will not be issuable in certificated form.

Certificated Debt Securities

You may transfer or exchange certificated debt securities at any office we maintain for this purpose in accordance with the terms of the indenture. No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange.

You may effect the transfer of certificated debt securities and the right to receive the principal of, premium and interest on certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

Global Debt Securities and Book-Entry System

Each global debt security will be deposited with, or on behalf of, the depositary, and registered in the name of the depositary or a nominee of the depositary. Beneficial interests in global debt securities will not be issuable in certificated form unless (i) the depositary has notified us that it is unwilling or unable to continue as depositary for such global debt security or has ceased to be qualified to act as such as required by the indenture and we fail to appoint a successor depositary within 90 days of such event, (ii) we determine, in our sole discretion, not to have such securities represented by one or more global securities or (iii) any other circumstances shall exist, in addition to or in lieu of those described above, as may be described in the applicable prospectus supplement. Unless and until a global debt security is exchanged for certificated debt securities under the limited circumstances described in the previous sentence, a global debt security may not be transferred except as a whole by the depositary to its nominee or by the nominee to the depositary, or by the depositary or its nominee to a successor depositary or to a nominee of the successor depositary.

Covenants

We will set forth in the applicable prospectus supplement any restrictive covenants applicable to any issue of debt securities.

No Protection In the Event of a Change of Control

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions which may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control) which could adversely affect holders of debt securities.

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Consolidation, Merger and Sale of Assets

Sonim may not consolidate with or merge with or into, or convey, transfer or lease all or substantially all of its assets to any person (a “successor person”) unless:

• Sonim is the surviving corporation or the successor person (if other than Sonim) is a corporation organized and validly existing under the laws of any U.S. domestic jurisdiction and expressly assumes Sonim’s obligations on the debt securities and under the indenture; and

• immediately after giving effect to the transaction, no default or event of default, shall have occurred and be continuing.

Notwithstanding the above, any of Sonim’s subsidiaries may consolidate with, merge into or transfer all or part of its properties to Sonim.

Events of Default

“Event of Default” means with respect to any series of debt securities, any of the following:

• default in the payment of any interest upon any debt security of that series when it becomes due and payable, and continuance of such default for a period of 30 days (unless the entire amount of the payment is deposited by us with the trustee or with a paying agent prior to the expiration of the 30-day period);

• default in the payment of principal of any security of that series at its maturity;

• default in the performance or breach of any covenant by us in the indenture (other than defaults described above or defaults relating to a covenant that has been included in the indenture solely for the benefit of a series of debt securities other than that series), which default continues uncured for a period of 60 days after we receive written notice from the trustee, or we and the trustee receive written notice from the holders of not less than 25% in principal amount of the outstanding debt securities of that series as provided in the indenture;

• certain voluntary or involuntary events of bankruptcy, insolvency or reorganization of Sonim; and

• any other event of default provided with respect to a series of debt securities, including any events of default relating to guarantors, if any, or subsidiaries that is described in the applicable prospectus supplement.

No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any other series of debt securities. The occurrence of certain events of default or an acceleration under the indenture may constitute an event of default under certain indebtedness of ours or our subsidiaries outstanding from time to time.

If an event of default with respect to any series of debt securities at the time outstanding occurs and is continuing (other than an event of default resulting from certain events of bankruptcy, insolvency or reorganization), then the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal of (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an event of default resulting from certain events of bankruptcy, insolvency or reorganization, the principal amount (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in principal

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amount of the outstanding debt securities of that series, by written notice to us and the trustee, may rescind and annul such declaration of acceleration and its consequences if all events of default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an event of default.

The indenture provides that the trustee will be under no obligation to perform any duty or exercise any of its rights or powers under the indenture unless the trustee receives indemnity satisfactory to it against any cost, liability or expense which might be incurred by it in performing such duty or exercising such right of power. Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series.

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

• that holder has previously given to the trustee written notice of a continuing event of default with respect to debt securities of that series;

• the holders of not less than 25% in principal amount of the outstanding debt securities of that series have made written request to the trustee to institute the proceedings in respect of such event of default in its own name as trustee under the indenture;

• such holder or holders have offered to the trustee indemnity or security satisfactory to the trustee against the costs, expenses and liabilities which might be incurred by the trustee in compliance with such request;

• the trustee has failed to institute any such proceeding for 60 days after its receipt of such notice, request and offer of indemnity; and

• no direction inconsistent with such written request has been given to the trustee during such 60-day period by holders of a majority in principal amount of the outstanding debt securities of that series.

Notwithstanding any other provision in the indenture, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, and any interest on, that debt security on or after the due dates expressed in that debt security (or, in the case of redemption, on the redemption date) and to institute suit for the enforcement of any such payment and such rights shall not be impaired without the consent of such holder.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture from our principal executive officer, principal financial officer or principal accounting officer. If a default or event of default occurs and is continuing with respect to the debt securities of any series and if it is actually known to a responsible officer of the trustee, the trustee shall mail to each holder of the debt securities of that series notice of a default or event of default within 60 days after it occurs or, if later, after a responsible officer of the trustee has knowledge of such default or event of default. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any default or event of default (except in payment on any debt securities of that series) with respect to debt securities of that series if the trustee determines in good faith that withholding notice is in the interest of the holders of those debt securities.

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Modification and Waiver

We and the trustee may modify and amend or supplement the indenture or the debt securities of one or more series without the consent of any holder of any debt security:

• to add guarantees with respect to debt securities of a series or secure debt securities of a series;

• to surrender any of our rights or powers under the indenture;

• to add covenants or events of default for the benefit of the holders of any series of debt securities;

• to comply with the applicable procedures of the applicable depositary;

• to cure any ambiguity, defect or inconsistency;

• to comply with covenants in the indenture described above under the heading “Consolidation, Merger and Sale of Assets”;

• to provide for uncertificated securities in addition to or in place of certificated securities;

• to make any change that does not materially adversely affect the rights of any holder of debt securities;

• to provide for the issuance of and establish the form and terms and conditions of debt securities of any series as permitted by the indenture;

• to effect the appointment of a successor trustee with respect to the debt securities of any series and to add to or change any of the provisions of the indenture to provide for or facilitate administration by more than one trustee;

• to comply with requirements of the SEC in order to effect or maintain the qualification of the indenture under the Trust Indenture Act; and

• for certain other reasons set forth in any prospectus supplement.

We may also modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments. We may not make any modification or amendment without the consent of the holders of each affected debt security then-outstanding if that amendment will:

• reduce the principal amount of debt securities whose holders must consent to an amendment, supplement or waiver;

• reduce the rate of or extend the time for payment of interest (including default interest) on any debt security;

• reduce the principal of, or change the fixed maturity of, any debt security or reduce the amount of, or postpone the date fixed for, the payment of any sinking fund or analogous obligation with respect to any series of debt securities;

• reduce the principal amount of discount securities payable upon acceleration of maturity;

• waive a default in the payment of the principal of, or interest, if any, on any debt security (except a rescission of acceleration of the debt securities of any series by the holders of at least a majority in principal amount of the then-outstanding debt securities of that series and a waiver of the payment default that resulted from such acceleration);

• make the principal of, or any interest on, any debt security payable in currency other than that stated in the debt security;

• make any change to certain provisions of the indenture relating to, among other things, the right of holders of debt securities to receive payment of the principal of, and any interest on, those debt securities and to institute suit for the enforcement of any such payment;

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• make any change to certain provisions of the indenture relating to waivers or amendments; or

• waive a redemption payment with respect to any debt security, provided that such redemption is made at our option.

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series may, on behalf of the holders of all debt securities of that series, by written notice to the trustee, waive our compliance with provisions of the indenture or the debt securities with respect to such series. The holders of a majority in principal amount of the outstanding debt securities of any series may, on behalf of the holders of all the debt securities of such series, waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, or any interest on, any debt security of that series; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance

The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, we may be discharged from any and all obligations in respect of the debt securities of any series (subject to certain exceptions). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. dollars, government obligations of the government that issued or caused to be issued such currency, that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants or investment bank to pay and discharge each installment of principal and interest, if any, on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the United States Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable United States federal income tax law, in either case to the effect that, and based thereon such opinion shall confirm that, the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

Defeasance of Certain Covenants

The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, upon compliance with certain conditions:

• we may omit to comply with the covenant described under the heading “Consolidation, Merger and Sale of Assets” and certain other covenants set forth in the indenture, as well as any additional covenants which may be set forth in the applicable prospectus supplement; and

• any omission to comply with those covenants will not constitute a default or an event of default with respect to the debt securities of that series (“covenant defeasance”).

The conditions include:

• depositing with the trustee money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. dollars, government obligations of the government that issued or caused to be issued such currency, that, through the payment of interest and principal in

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• accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants or investment bank to pay and discharge each installment of principal of, and interest, if any, on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities; and

• delivering to the trustee an opinion of counsel to the effect that the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit and related covenant defeasance and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit and related covenant defeasance had not occurred.

Governing Law

The indenture and the debt securities, including any claim or controversy arising out of or relating to the indenture or the securities, will be governed by the laws of the State of New York (without regard to the conflicts of laws provisions thereof other than Section 5-1401 of the General Obligations Law).

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DESCRIPTION OF WARRANTS

General

The following description, together with the additional information we include in any applicable prospectus supplement, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which consist of warrants to purchase shares of common stock, preferred stock and/or debt securities in one or more series. Warrants may be offered independently or together with shares of common stock, preferred stock and/or debt securities offered by any prospectus supplement and may be attached to or separate from those securities.

While the terms we have summarized below will generally apply to any future warrants we may offer under this prospectus, we will describe the particular terms of any warrants that we may offer in more detail in the applicable prospectus supplement. The specific terms of any warrants may differ from the description provided below as a result of negotiations with third parties in connection with the issuance of those warrants, as well as for other reasons. Because the terms of any warrants we offer under a prospectus supplement may differ from the terms we describe below, you should rely solely on information in the applicable prospectus supplement if that summary is different from the summary in this prospectus.

We will issue the warrants under a warrant agreement, which we will enter into with a warrant agent to be selected by us. We use the term “warrant agreement” to refer to any of these warrant agreements. We use the term “warrant agent” to refer to the warrant agent under any of these warrant agreements. The warrant agent will act solely as an agent of ours in connection with the warrants and will not act as an agent for the holders or beneficial owners of the warrants.

We will incorporate by reference into the registration statement of which this prospectus is a part the form of warrant agreement, including a form of warrant certificate, that describes the terms of the series of warrants we are offering before the issuance of the related series of warrants. The following summaries of material provisions of the warrants and the warrant agreements are subject to, and qualified in their entirety by reference to, all the provisions of the warrant agreement applicable to a particular series of warrants. We urge you to read any applicable prospectus supplement related to the warrants that we sell under this prospectus, as well as the complete warrant agreement that contain the terms of the warrants and defines your rights as a warrant holder.

We will describe in the applicable prospectus supplement the terms relating to a series of warrants. If warrants for the purchase of debt securities are offered, the prospectus supplement will describe the following terms, to the extent applicable:

• the offering price and the aggregate number of warrants offered;

• the currencies in which the warrants are being offered;

• the designation, aggregate principal amount, currencies, denominations and terms of the series of debt securities that can be purchased if a holder exercises a warrant;

• the designation and terms of any series of debt securities with which the warrants are being offered and the number of warrants offered with each such debt security;

• the date on and after which the holder of the warrants can transfer them separately from the related series of debt securities;

• the terms of any rights to redeem or call the warrants;

• the date on which the right to exercise the warrants begins and the date on which that right expires;

• federal income tax consequences of holding or exercising the warrants; and

• any other specific terms, preferences, rights or limitations of, or restrictions on, the warrants.

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Warrants for the purchase of debt securities will be in registered form only.

If warrants for the purchase of shares of common stock or preferred stock are offered, the prospectus supplement will describe the following terms, to the extent applicable:

• the offering price and the aggregate number of warrants offered;

• the total number of shares that can be purchased if a holder of the warrants exercises them;

• the number of warrants being offered with each share of common stock;

• the date on and after which the holder of the warrants can transfer them separately from the related shares of common stock or preferred stock;

• the number of shares of common stock or preferred stock that can be purchased if a holder exercises the warrant and the price at which those shares may be purchased upon exercise, including, if applicable, any provisions for changes to or adjustments in the exercise price and in the securities or other property receivable upon exercise;

• the terms of any rights to redeem or call, or accelerate the expiration of, the warrants;

• the date on which the right to exercise the warrants begins and the date on which that right expires;

• federal income tax consequences of holding or exercising the warrants; and

• any other specific terms, preferences, rights or limitations of, or restrictions on, the warrants.

Warrants for the purchase of shares of common stock or preferred stock will be in registered form only.

A holder of warrant certificates may exchange them for new certificates of different denominations, present them for registration of transfer and exercise them at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement. Until any warrants to purchase debt securities are exercised, the holder of the warrants will not have any of the rights of holders of the debt securities that can be purchased upon exercise, including any rights to receive payments of principal, premium or interest on the underlying debt securities or to enforce covenants in the applicable indenture. Until any warrants to purchase shares of common stock or preferred stock are exercised, holders of the warrants will not have any rights of holders of the underlying shares of common stock or preferred stock, including any rights to receive dividends or to exercise any voting rights, except to the extent set forth under “Warrant Adjustments” below.

Exercise of Warrants

Each holder of a warrant is entitled to purchase the principal amount of debt securities or number of shares of common stock or preferred stock, as the case may be, at the exercise price described in the applicable prospectus supplement. After the close of business on the day when the right to exercise terminates (or a later date if we extend the time for exercise), unexercised warrants will become void.

A holder of warrants may exercise them by following the general procedure outlined below:

• deliver to the warrant agent the payment required by the applicable prospectus supplement to purchase the underlying security;

• properly complete and sign the reverse side of the warrant certificate representing the warrants; and

• deliver the warrant certificate representing the warrants to the warrant agent within five business days of the warrant agent receiving payment of the exercise price.

If you comply with the procedures described above, your warrants will be considered to have been exercised when the warrant agent receives payment of the exercise price, subject to the transfer books for the securities issuable upon exercise of the warrant not being closed on such date. After you have completed those procedures

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and subject to the foregoing, we will, as soon as practicable, issue and deliver to you the debt securities or shares of common stock or preferred stock that you purchased upon exercise. If you exercise fewer than all of the warrants represented by a warrant certificate, a new warrant certificate will be issued to you for the unexercised amount of warrants. Holders of warrants will be required to pay any tax or governmental charge that may be imposed in connection with transferring the underlying securities in connection with the exercise of the warrants.

Amendments and Supplements to the Warrant Agreements

We may amend or supplement a warrant agreement without the consent of the holders of the applicable warrants to cure ambiguities in the warrant agreement, to cure or correct a defective provision in the warrant agreement, or to provide for other matters under the warrant agreement that we and the warrant agent deem necessary or desirable, so long as, in each case, such amendments or supplements do not materially adversely affect the interests of the holders of the warrants.

Warrant Adjustments

Unless the applicable prospectus supplement states otherwise, the exercise price of, and the number of securities covered by, a warrant for shares of common stock or preferred stock will be adjusted proportionately if we subdivide or combine our common stock or preferred stock, as applicable. In addition, unless the prospectus supplement states otherwise, if we, without payment:

• issue shares of common stock or preferred stock or other securities convertible into or exchangeable for common stock or preferred stock, or any rights to subscribe for, purchase or otherwise acquire any of the foregoing, as a dividend or distribution to all or substantially all holders of our common stock or preferred stock;

• pay any cash to all or substantially all holders of our common stock or preferred stock, other than a cash dividend paid out of our current or retained earnings;

• issue any evidence of our indebtedness or rights to subscribe for or purchase our indebtedness to all or substantially all holders of our common stock or preferred stock; or

• issue common stock, preferred stock or additional shares or other securities or property to all or substantially all holders of our common stock or preferred stock by way of spinoff, split-up, reclassification, combination of shares or similar corporate rearrangement;

then the holders of common stock warrants or preferred stock warrants will be entitled to receive upon exercise of the warrants, in addition to the securities otherwise receivable upon exercise of the warrants and without paying any additional consideration, the amount of shares and other securities and property such holders would have been entitled to receive had they held the common stock or preferred stock issuable under the warrants on the dates on which holders of those securities received or became entitled to receive such additional shares and other securities and property.

Except as stated above, the exercise price and number of securities covered by a warrant for shares of common stock or preferred stock, and the amounts of other securities or property to be received, if any, upon exercise of those warrants, will not be adjusted or provided for if we issue those securities or any securities convertible into or exchangeable for those securities, or securities carrying the right to purchase those securities or securities convertible into or exchangeable for those securities.

Holders of common stock warrants or preferred stock warrants may have additional rights under the following circumstances:

• certain reclassifications, capital reorganizations or changes of the common stock or preferred stock;

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• certain share exchanges, mergers, or similar transactions involving us that result in changes of the common stock or preferred stock; or

• certain sales or dispositions to another entity of all or substantially all of our property and assets.

If one of the above transactions occurs and holders of our common stock or preferred stock are entitled to receive shares, securities or other property with respect to or in exchange for their securities, the holders of the common stock warrants or preferred stock warrants then-outstanding, as applicable, will be entitled to receive upon exercise of their warrants the kind and amount of shares and other securities or property that they would have received upon the applicable transaction if they had exercised their warrants immediately before the transaction.

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DESCRIPTION OF RIGHTS

The following description, together with the additional information we include in any applicable prospectus supplement, summarizes the general features of the rights that we may offer under this prospectus. We may issue rights to our stockholders to purchase shares of our common stock and/or any of the other securities offered hereby. Each series of rights will be issued under a separate rights agreement to be entered into between us and a bank or trust company, as rights agent. When we issue rights, we will provide the specific terms of the rights and the applicable rights agreement in a prospectus supplement. Because the terms of any rights we offer under a prospectus supplement may differ from the terms we describe below, you should rely solely on information in the applicable prospectus supplement if that summary is different from the summary in this prospectus. We will incorporate by reference into the registration statement of which this prospectus is a part the form of rights agreement that describes the terms of the series of rights we are offering before the issuance of the related series of rights. The applicable prospectus supplement relating to any rights will describe the terms of the offered rights, including, where applicable, the following:

• the date for determining the persons entitled to participate in the rights distribution;

• the exercise price for the rights;

• the aggregate number or amount of underlying securities purchasable upon exercise of the rights;

• the number of rights issued to each stockholder and the number of rights outstanding, if any;

• the extent to which the rights are transferable;

• the date on which the right to exercise the rights will commence and the date on which the right will expire;

• the extent to which the rights include an over-subscription privilege with respect to unsubscribed securities;

• anti-dilution provisions of the rights, if any; and

• any other terms of the rights, including terms, procedures and limitations relating to the distribution, exchange and exercise of the rights.

Holders may exercise rights as described in the applicable prospectus supplement. Upon receipt of payment and the rights certificate properly completed and duly executed at the corporate trust office of the rights agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the securities purchasable upon exercise of the rights. If less than all of the rights issued in any rights offering are exercised, we may offer any unsubscribed securities directly to persons other than stockholders, to or through agents, underwriters or dealers or through a combination of such methods, including pursuant to standby underwriting arrangements, as described in the applicable prospectus supplement.

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DESCRIPTION OF UNITS

We may issue units comprising two or more securities described in this prospectus in any combination. For example, we might issue units consisting of a combination of debt securities and warrants to purchase common stock. The following description sets forth certain general terms and provisions of the units that we may offer pursuant to this prospectus. The particular terms of the units and the extent, if any, to which the general terms and provisions may apply to the units so offered will be described in the applicable prospectus supplement.

Each unit will be issued so that the holder of the unit also is the holder of each security included in the unit. Thus, the unit will have the rights and obligations of a holder of each included security. Units will be issued pursuant to the terms of a unit agreement, which may provide that the securities included in the unit may not be held or transferred separately at any time or at any time before a specified date. A copy of the forms of the unit agreement and the unit certificate relating to any particular issue of units will be filed with the SEC each time we issue units, and you should read those documents for provisions that may be important to you. For more information on how you can obtain copies of the forms of the unit agreement and the related unit certificate, see “Where You Can Find More Information.”

The prospectus supplement relating to any particular issuance of units will describe the terms of those units, including, to the extent applicable, the following:

• the designation and terms of the units and the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

• any provision for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units; and

• whether the units will be issued in fully registered or global form.

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PLAN OF DISTRIBUTION

We may sell the securities from time to time, by a variety of methods, including the following:

• on any national securities exchange or quotation service on which our securities may be listed at the time of sale, including the Nasdaq Global Market;

• in the over-the-counter market;

• in transactions otherwise than on such exchange or in the over-the-counter market, which may include privately negotiated transactions and sales directly to one or more purchasers;

• through ordinary brokerage transactions and transactions in which the broker-dealer solicits purchasers;

• through purchases by a broker-dealer as principal and resale by the broker-dealer for its account;

• through underwriters, broker-dealers, agents, in privately negotiated transactions, or any combination of these methods;

• through short sales;

• through the writing or settlement of options or other hedging transactions, whether through an options exchange or otherwise;

• a combination of any of these methods; or

• by any other method permitted pursuant to applicable law.

The securities may be distributed from time to time in one or more transactions:

• at a fixed price or prices, which may be changed;

• at market prices prevailing at the time of sale;

• at prices related to such prevailing market prices; or

• at negotiated prices.

Offers to purchase the securities being offered by this prospectus may be solicited directly. Agents may also be designated to solicit offers to purchase the securities from time to time. Any agent involved in the offer or sale of our securities will be identified in a prospectus supplement.

If a dealer is utilized in the sale of the securities being offered by this prospectus, the securities will be sold to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale.

If an underwriter is utilized in the sale of the securities being offered by this prospectus, an underwriting agreement will be executed with the underwriter at the time of sale and the name of any underwriter will be provided in the prospectus supplement that the underwriter will use to make resales of the securities to the public. In connection with the sale of the securities, we, or the purchasers of securities for whom the underwriter may act as agent, may compensate the underwriter in the form of underwriting discounts or commissions. The underwriter may sell the securities to or through dealers, and those dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for which they may act as agent. Unless otherwise indicated in a prospectus supplement, an agent will be acting on a best efforts basis and a dealer will purchase securities as a principal, and may then resell the securities at varying prices to be determined by the dealer.

Any compensation paid to underwriters, dealers or agents in connection with the offering of the securities, and any discounts, concessions or commissions allowed by underwriters to participating dealers will be provided in

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the applicable prospectus supplement. Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters within the meaning of the Securities Act, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions. In compliance with the guidelines of the Financial Industry Regulatory Authority, Inc., or FINRA, the maximum amount of underwriting compensation, including underwriting discounts and commissions, to be paid in connection with any offering of securities pursuant to this prospectus may not exceed 8% of the aggregate principal amount of securities offered. We may enter into agreements to indemnify underwriters, dealers and agents against civil liabilities, including liabilities under the Securities Act, or to contribute to payments they may be required to make in respect thereof and to reimburse those persons for certain expenses.

The securities may or may not be listed on a national securities exchange. To facilitate the offering of securities, certain persons participating in the offering may engage in transactions that stabilize, maintain or otherwise affect the price of the securities. This may include over-allotments or short sales of the securities, which involve the sale by persons participating in the offering of more securities than were sold to them. In these circumstances, these persons would cover such over-allotments or short positions by making purchases in the open market or by exercising their over-allotment option, if any. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing securities in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

If indicated in the applicable prospectus supplement, underwriters or other persons acting as agents may be authorized to solicit offers by institutions or other suitable purchasers to purchase the securities at the public offering price set forth in the prospectus supplement, pursuant to delayed delivery contracts providing for payment and delivery on the date or dates stated in the prospectus supplement. These purchasers may include, among others, commercial and savings banks, insurance companies, pension funds, investment companies and educational and charitable institutions. Delayed delivery contracts will be subject to the condition that the purchase of the securities covered by the delayed delivery contracts will not at the time of delivery be prohibited under the laws of any jurisdiction in the United States to which the purchaser is subject. The underwriters and agents will not have any responsibility with respect to the validity or performance of these contracts.

We may engage in at-the-market offerings into an existing trading market in accordance with rule 415(a)(4) under the Securities Act. In addition, we may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement so indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us, or borrowed from us or others to settle those sales or to close out any related open borrowings of common stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of our common stock. In addition, we may loan or pledge securities to a financial institution or other third party that in turn may sell the securities using this prospectus and an applicable prospectus supplement. Such financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

The underwriters, dealers and agents may engage in transactions with us, or perform services for us, in the ordinary course of business for which they receive compensation.

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LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, certain legal matters in connection with the offering and the validity of the securities offered by this prospectus, and any supplement thereto, will be passed upon by O’Melveny  & Myers LLP.

EXPERTS

The consolidated financial statements of Sonim Technologies, Inc. incorporated in this Registration Statement on Form S-3 by reference from Sonim Technologies, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2020 have been audited by Moss Adams LLP, an independent registered public accounting firm, as set forth in their report which is incorporated by reference herein. Such consolidated financial statements have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.

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Up to $41,636,612

Common Stock

PROSPECTUS SUPPLEMENT

B. Riley Securities

September 24, 2021