Check the Trash, Recently Deleted, or Bin folder in your contacts app or email account
Restore contacts from your phone’s backup service
Restore contacts from iCloud if you use an iPhone
Restore contacts from Google Contacts if you use Android or Gmail
Sync your contacts account again to refresh deleted entries
Check other devices signed into the same account for the missing contacts
Export and restore contacts from a previous backup file
Use a data recovery tool if no backup is available
Contact your phone carrier or device support if the contacts were stored there
Re-enter the contacts manually if recovery is not possible