Check the Contacts app and search for the missing contact
Open the Phone app and check Recents for the number
Check Messages and email for the contact’s phone number or email address
Restore contacts from iCloud.com if Contacts sync was enabled
Go to iPhone Settings > [your name] > iCloud > Contacts and turn Contacts on
Sign in to iCloud.com on a browser and check Contacts
Restore an earlier iCloud backup if the contact was deleted before the backup
Restore from a computer backup made with Finder or iTunes
Check Google Contacts if your account was synced to the iPhone
Check other synced accounts such as Outlook, Yahoo, or Exchange
Use the Contacts app’s groups or account filters to show all contacts
Check recently deleted contacts in the source account if available
Ask the contact to send their details again
Use third-party data recovery software only if needed and from a trusted source