Company: SONM
Filing Date: 2025-07-09
Form Type: DEFA14A
Source: 0001641172-25-018308
Chunk: 0

Company: SONIM TECHNOLOGIES INC
Filing Date: 2025-07-09
Form: DEFA14A
Chunk 0
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<div align='center'>UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934</div>

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

| ☐ | Preliminary                                                       
 Proxy Statement                                                   |
| ☐ | Confidential,                                                     
 for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) |
| ☐ | Definitive                                                        
 Proxy Statement                                                   |
| ☒ | Definitive                                                        
 Additional Materials                                              |
| ☐ | Soliciting                                                        
 Material under §240.14a-12                                        |

<div align='center'>Sonim Technologies, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)</div>

Payment of Filing Fee (Check all boxes that apply):

| ☒ | No           
 fee required |

| ☐ | Fee                                        
 paid previously with preliminary materials |

| ☐ | Fee                                                                                             
 computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11 |

The following e-mails were distributed to certain employees of the registrant on July 8, 2025:

<div align='center'>***</div>

Dear Team,

Just a friendly reminder: if you or any of your friends or family have Sonim shares bought independently through an external agency, you can get assistance with voting those shares from the Sodali team. Feel free to reach out to them at SONM@investor.sodali.com, and they’ll be more than happy to help you with the voting process.

温馨提醒：如果您或您的朋友或家人 通过外部机构独立购买了Sonim股票，Sodali团队可以协助您进行投票。 请通过SONM@investor.sodali.com与他们联系，他们会非常乐意为您提供帮助。

<div align='center'>***</div>

Team,

Reminder that any questions or assistance specific to the WHITE card for proxy voting, are to be directed to your broker directly or