Hide duplicate contacts on iPhone
In the Contacts app , link contact cards for the same person in different accounts so they appear only once in your All Contacts list. When you have contacts from multiple sources, you might have multiple entries for the same person in Contacts. To keep redundant contacts from appearing in your All Contacts list, contacts from different sources with the same name are linked and displayed as a single unified contact. When you view a unified contact, the title Unified Info appears.
If two entries for the same person aren’t linked automatically, you can unify them manually.
Tap one of the contacts, tap Edit, then tap Link Contacts.
Choose the other contact entry to link to, then tap Link.
When you link contacts with different first or last names, the names on the individual cards don’t change, but only one name appears on the unified card. To choose which name appears on the unified card, tap one of the linked cards, tap the contact’s name on that card, then tap Use This Name For Unified Card.
Note: When you link contacts, those contacts aren’t merged. If you change or add information in a unified contact, the changes are copied to each source account where that information already exists.