Check the Contacts app and refresh or sync your account
Sign in to your Google, iCloud, or other backup account
Restore contacts from a recent cloud backup
Check the Trash, Recently Deleted, or Bin folder in your contacts app
Restore contacts from your SIM card if they were saved there
Import contacts from a VCF, CSV, or backup file
Use a phone backup tool or recovery app
Connect the phone to a computer and recover from a local backup
Check other synced devices for the missing contacts
Contact your carrier if contacts were stored through their service