The Postal Service provides one-time use pins via SMS text messages to authenticate External Digital Signature users as part of our Two Factor Authentication (2FA). In order to participate in digitally signing a document, the external users provide their cell numbers to Postal individuals over email or phone conversations. This is purely voluntary — if the external party chooses to not participate in digitally signing a document, they can simply opt-out by declining the offer made by a Postal employee.

Digital Signature Text Messaging (Short Code 96429)

• Opt-In - this process is started by a Postal employee inviting an external user, either over the phone, or by email. Postal Service DSign system will never send unsolicited SMS messages to any user. You may decline receiving SMS messages for the purpose of digitally signing documents when solicited by a Postal employee.
• Help Message - this message is generated when "HELP" is texted back to the USPS Digital Signature Text Messaging SMS number 96429 (message & data rates may apply).
• Stop Message - this message is generated when "STOP" is texted to the USPS Digital Signature Text Messaging SMS number 96429 (message & data rates may apply).

Supported Phone Numbers
The Postal Service Digital Signature supports SMS text messaging for domestic and international users.

Participating carriers include AT&T, T-Mobile®, Verizon Wireless, Sprint, Boost, U.S. Cellular®, MetroPCS, Virgin Mobile, and Cricket - PLEASE CONTACT YOUR TELECOMMUNICATIONS PROVIDER FOR FURTHER DETAILS.

Privacy Act Statement
Your cell phone number will be used for USPS Digital Signature Two-Factor Authentication. Providing the information is voluntary, but if not provided, we will be unable to offer this service to you. We do not disclose your information to third parties and your cell phone number is expressly used to facilitate Digital Signature transactions only.

You may access our full privacy policy by visiting www.usps.com/privacypolicy.