A person can appear twice in Contacts because their details are stored in two accounts. Linking those cards creates a combined view, but it does not remove the underlying account records. Establish which account owns each card before trying to tidy the list.

Open the cards and compare more than the person’s name. Check email addresses, phone numbers and organisation details to confirm they refer to the same person. Two people with identical names should not be linked merely to reduce the number of search results.

Choose linking for the cross-account view

Apple describes linking as keeping each account’s card while displaying one card with combined information. Select the intended cards and choose Card, Link Selected Cards. Open the resulting card and inspect the accounts listed in its cards section.

Merging solves a different problem: duplicate cards within an account. Apple’s Merge Selected Cards command combines unique information into one card. Preserve an appropriate export before merging valuable records and avoid a broad duplicate operation until you understand its scope.

Check where later edits will go

Apple warns that edits to a linked card appear in the linked card and the listed accounts; contact pictures have a documented exception. Do not use a harmless-looking edit to experiment on a business record if you are unsure which account will receive the change.

If the link is wrong, open the linked card, choose Edit and use the remove control for the relevant account to unlink it. Confirm that the separate cards now appear as expected and that their information is still present.

A combined view is useful for finding a person, but it does not establish which account should be the long-term authority for their details. Record that decision separately when preparing an account handover.

Finish by searching for the person again and checking the selected card’s source accounts. The intended result is an understandable view of the right person, with account ownership still clear, rather than simply the smallest possible contact count.

References: Apple: linked contacts, Apple: merging contact cards.