Check the device’s built-in Recently Deleted/Trash folder (Messages app or equivalent)
Restore from iCloud backup (iPhone) or Google backup (Android) if the backup includes messages
If you use a third-party messaging app, check its in-app backup/restore options
Use the carrier’s message backup service if your plan/device supports it
For iPhone: restore from an iCloud backup via Settings > General > Transfer or Reset iPhone > Erase All Content and Settings, then restore during setup
For Android: restore from Google backup via Settings > System > Backup > Restore (availability varies by device/OS)
If messages were synced to a computer (e.g., iMessage on Mac), check synced message history there
If the messages were in a cloud account (e.g., some SMS/MMS cloud services), sign in on the provider’s website/app and check message history
Contact the messaging app or service provider support for any recovery options
If you need forensic recovery, stop using the device immediately and consult a professional data recovery service