You can permanently disable your phone number from being recognized as a Signal user by unregistering your phone number.

Visit https://signal.org/signal/unregister/ or follow the steps for your platform:

• Android
• iOS
• Desktop

Android

Follow steps to unregister:

1. Open Signal.
2. Tap on the Menu.
3. Choose Settings.
4. Tap on Advanced.
5. Tap 'Signal messages and calls' to slide the indicator off.
6. Choose OK.

iOS

Follow steps to unregister and delete your message history on this iPhone:

1. Open Signal.
2. Go to Settings . 
3. Tap the red Delete Account button.
4. Tap Proceed to confirm.

Desktop

Follow steps to delete your message history on this Desktop:

1. Open Signal.
2. Navigate to Preferences.
   - Mac: Go to Signal > Preferences.
   - Windows: Go to File > Preferences.
   - Linux: Go to File > Preferences.
3. Select Clear Data.
4. Select Delete All Data to confirm.