What it means
Signal's PIN helps recover profile information, settings, contacts and block list, and may serve registration lock. It does not store or restore your chat history. History needs a supported backup or transfer with its own prerequisites and recovery secret.
A real-world example
A user remembers the Signal PIN on a new phone and regains account-related settings, but discovers old conversations are absent because no message backup or transfer was made.
What to do
Save the PIN independently and prepare a separate chat-history migration before retiring the old phone. Review registration-lock consequences so a forgotten PIN does not delay re-entry.
The distinction that matters
The PIN is also different from the SMS code used during registration and the device passcode used to unlock the phone. Signal cannot reveal or reset an unknown PIN; with registration lock, forgetting it can mean waiting for the documented inactivity period.
Signal PIN's actual scope
