Handling unknown phone numbers - new users

You may find that once you get SMS up and running with Braze that you receive messages from unknown users. The following article list the steps through which an unidentified user and number get processed.

Braze can automatically create a user when a user with a new phone number responds with a START or STOP (or any other variation of these keywords). When creating the user, Braze will set their phone field with the E.164 number provided by our SMS provider. In addition, the user alias (‘phone’) will be set with the same value.

Customers can use the user attributes object in tandem with the /users/track endpoint to find users based on their alias and set an external_id.

Opt-in/out and custom keyword workflow for unknown numbers

Braze automatically addresses an unknown number in one of three ways:

1. If an opt-in keyword is texted:
   • Braze creates an anonymous profile
   • Our system sets the phone attribute
   • Subscribes the user to the corresponding subscription group based on what opt-in keyword was received by Braze.
     
     
2. If an opt-out keyword is texted:
   • Braze creates an anonymous profile
   • Our system sets the phone attribute
   • Unsubscribes the user from the corresponding subscription group based on what opt-out keyword was received by Braze.
     
     
3. If any other custom keyword is texted:
   • Braze ignores the text message and does nothing.