Signal is the best encrypted-messaging app, most security and privacy experts say. But one of its biggest drawbacks has been that Signal accounts are tied to phone numbers. As a consequence, you haven't been able to port an account to a new number, instead having to start over from scratch and losing your message history.
Until now, that is. In a blog post yesterday (February 7), Signal's Jim O'Leary announced that the company would finally let users move accounts over to new numbers on both iOS and Android.
"We now provide the ability to change the phone number on your Signal account, while retaining all of your chats, profile information, and groups," O'Leary wrote. "The Change Number feature will let you keep your profile and all of your existing messages and groups on your device, while making you reachable at your new phone number."
You can't always change numbers, however
There are couple of catches. First of all, the change from an old number to a new number has to happen on the same phone. You can't change numbers and change phones at the same time, and you won't be able to regain an account from a lost or damaged phone.
Second, the phone has to be running the latest version of Signal, which on Android is currently 5.30.6 and on iOS, 5.27.1. Finally, the Signal app has to be able to send and receive messages and can't be malfunctioning for whatever reason.
Full instructions for changing the number are found on the "Change Number" support article on the Signal website.
Basically, you tap on your profile icon in the Signal app, go into the account settings (Settings > Account on iOS, but just Account on Android) and look for the "Change Phone Number" option. (This didn't show up on our old OnePlus 5 despite the app being up-to-date; your mileage may vary.)
From there, you enter the old number and the new number; you then tap Continue or Done and confirm that the information is correct. You can edit either number if you made a typo. (Signal is very clear that Change Number is a one-way process that cannot be reversed.)
You then select Change Number and go through the regular registration process. Your contacts and message history should be preserved.
Once the change goes through, O'Leary said, your contacts will get a message notifying them that you have changed their phone number, with an invitation to update your information in their Signal contact lists.
Transferring accounts between phones
Signal already makes it possible to transfer accounts between one Android device and another, or one iOS device and another, as long as the phone number doesn't change. Basically, you need to install the Signal app on your new phone or tablet, then go into Account as above and select Transfer Account.
The big caveat is that you can't transfer accounts between an iOS and an Android device in either direction. If you're doing that, you have to start over from scratch on the new device — even if you're using the same number as before.
If you want to change both your phone and your number, then you could in theory do it in a two-step process as long as you're staying all-Android or all-iOS. First, you would change the number as above. Then once that is all set up, follow the account-transfer process.
We've got lots more about setting up and using the messaging app in our guide on how to use Signal.