How to Merge Duplicate Contacts on iPhone

TL;DR

Swipe Clean matches contacts by the same phone number (last 10 digits), same email or same name, merges each group into the first contact with all numbers, emails and addresses combined, and deletes the extras. It also lists empty or incomplete contacts. Review each group, since a merge is not reversible in the app.

The problem

Years of syncing, importing, shared cards and a switched phone leave you with three “Mom” entries, a “John” with just an email and a contact that’s only a blank row. Search returns five results, and you’re never sure which number is the current one.

Cleaning contacts by hand is slow and risky, so most people never do it.

How matching works

Swipe Clean looks for three kinds of overlap:

  • Same phone number. Numbers are stripped of formatting and compared by their last 10 digits (and need at least 5 digits to count).
  • Same email, ignoring capitals.
  • Same name (first and last).

Each group shows why it matched (“Same phone number”, “Same email”, “Same name”).

It also builds an Incomplete list for contacts that are empty, have no name, or have neither a phone nor an email.

What a merge does

For each group, the app keeps the first contact and:

  • adds phone numbers and emails from the others, skipping ones it already has;
  • adds their addresses;
  • fills in a missing first name, last name or company;
  • deletes the other entries.

How to do it

  1. Open More tools → Contacts and allow access.
  2. In Duplicates, open a group and read the entries and the match reason.
  3. Merge only the ones you’re sure about.
  4. In Incomplete, fill in or delete the entries you don’t need.

Check before you merge

  • “Same name” can be two people. Two different “John Smith”s will be grouped. Look at the numbers.
  • The last-10-digits rule means the same local number in two different countries can match. Look at the country codes.
  • The first contact wins for a name or company clash, so make sure the better entry is the first.
  • Merges can’t be undone in the app. For a large cleanup, check you have a contacts backup first (for example in iCloud).

Privacy

Matching runs on your device, and nothing leaves it.

FAQ

How does it decide two contacts are duplicates? They share a phone number (compared by the last 10 digits), the same email address, or the same first and last name.

What happens when I merge? The first contact in the group is kept, phone numbers, emails and addresses from the others are added to it (without repeating the same ones), blank name or company fields are filled in, and the other entries are deleted.

Can I undo a merge? Not inside the app. Check each group before merging, and if you’re worried make sure you have a backup of your contacts.

Is it free? Contact cleanup is not behind the Premium paywall.

Are contacts uploaded? No. Matching happens on the phone.

The app Swipe Clean Photos →