Signal will send a single SMS message to the number that is trying to register with Signal. Signal sends a verification code to make sure you have ownership of the phone number you are registering with.
Below is what the text message will look like, where the actual verification code will change in each text.
- If registering from an iPhone the text message shows
"Your Signal verification code: 350-999 Or tap: sgnl://verify/350-999"
- If registering from an Android Phone the text message* shows
"Your Signal verification code: 934-269"
The 6-digit verification code is used only once to complete registration. Please do not share this one time use verification code with anyone else. Once registration is done, the phone that just registered will be able to send and receive all new Signal messages and calls.
*On Android phones the verification SMS is automatically picked up by Signal and can not be typed in. Signal Android users can only type in a verification code that was received by a call.