Audit Signal linked devices and registration lock

Signal supports linked devices, but its PIN and registration lock solve different problems. The PIN is not a chat backup, and turning on registration lock without remembering that PIN can leave you unable to re-register for up to seven days. Review your current devices before changing settings during an account scare.

Check without deleting conversations​

1. On the primary phone, open Signal Settings → Linked devices. Compare the list with the computers and secondary devices you use. Unlink a device you do not recognize; do not reinstall Signal simply to perform this check.
2. If the phone says it is no longer registered, someone may have registered the number on another primary device, or you may have set up a replacement phone. Follow Signal's in-app re-registration flow and secure your mobile account if you suspect a number transfer.
3. While your primary phone is active, open Settings → Account to review the PIN and optional Registration Lock. Store a strong PIN where you can recover it. Enable the lock only after understanding the waiting period if you lose the PIN.
4. Tell sensitive contacts to verify your identity using another channel if unexpected messages were sent. Review your device's screen lock and installed apps; a person with physical access can be a separate risk.

Avoid a common recovery mistake​

A Signal PIN can restore profile and contact-related settings, but it does not restore lost message history. Plan chat backup or transfer separately. Signal's linked-device guide and PIN explanation describe the current controls. If your SIM or mobile service unexpectedly stops working, see our SIM-swap guide and contact your carrier promptly.