Suppose you accidentally deleted any of your important contact on iPhone and need it back, then just follow the guide written below to recover your lost contact on iPhone.
Restore Lost Contacts on an iPhone
Attach your iPhone to computer and launch iTunes
In iTunes window click on “Devices” in left column and select your attached iPhone there, right click (Windows), ctrl + click (Mac) on it and click on “Restore from Backup…” option from menu
Restore process will sync all of your lost contacts on your iPhone whatever you have saved in your backup and that’s it.