Android has no system-wide SMS trash, but backups and app-level bins mean deleted messages are often recoverable, if a backup existed before the deletion.
- 1Google Messages: check Archived (menu → Archived), 'deleted' threads are often just archived.
- 2Restore from Google backup: a phone reset restores SMS included in Settings → Google → Backup.
- 3Samsung users: Samsung Cloud/Smart Switch backups also include messages.
- 4WhatsApp: uninstall and reinstall, then restore the Google Drive chat backup at setup.
- 5Carrier route: some carriers can provide message logs (not content) for legal purposes.
Tip: Enable automatic backups now, recovery is only ever as good as the last backup made before deletion.