Contacts icon It’s not unusual for peoples names to change, for someone to switch jobs or phone numbers, or even for a company to change their name or information. It’s frustrating to wander into the Contacts app on the iPhone to discover a ton of entries for a single person or entity to cover each of those changes, so when you find your Contacts getting overrun with duplicates or multiple entries for a single person, take the time to clean them up, merge the contacts, and eliminate the duplicates.

The easiest way to merge existing contacts into a single contact is to use the Contacts app in Mac OS X. Because Contacts syncs through iCloud (or manually through iTunes, if you’d prefer that approach), changes and merges made on the Mac will instantly transfer back to the iPhone, where the two (or more) contacts will be merged into one. The only limitation, other than having a Mac of course, is that both the Mac and the iPhone be using the same iCloud account.

Merge Multiple Contacts Into One

Want to merge a few contacts or duplicates that were not picked up by the built-in duplicate finder? Use the individual merging feature:

  • Select two or more contacts by command+clicking on the contacts you wish to merge together

  • Once two or more contacts have been selected, pull down the Card menu and choose “Merge Selected Cards”

Yes, individual contacts are called “Cards”.

Merge multiple contacts into one for iPhone

Unlike the more general Duplicate finder, there is no warning or confirmation, and the contacts are instantly merged into one.

I accidentally merged some Contacts, help!

Merged a contact or several that you now regret? Maybe you accidentally merged your boss and your mom? No big deal as long as you address it quickly, you can undo any Contact merge just like you can any other task by hitting Command+Z, or by pulling down the Edit menu and selecting “Undo Merge”. OS X maintains a history to the Undo menu as well, so you can repeatedly hit Command+Z inside of Contacts app to undo more than once, or even if the merge you’re trying to undo is several steps back.

The undo feature is helpful, but if you’re going to be making a lot of adjustments to Contacts it may be a good idea to back everything up first so you can revert if something goes awry. Assuming you have iCloud configured, the Contacts should automatically back themselves up, but you can also do it yourself or initiate a manual backup.

Find & Merge Duplicate Contacts

You can also let Contacts merge duplicates for you by using the “Look For Duplicates” feature. This also works in Address Book, which is basically the same app pre-10.8:

  • Open Contacts app in OS X, found in /Applications/

  • Pull down the “Card” menu and choose “Look for Duplicates”

Find and fix duplicates in the Contacts app

If contacts are found to be duplicates, choose “Merge” to combine them into one.

Merge duplicates in Contacts to sync with iPhone

The “Look for Duplicate” feature is fairly effective, but because it focuses on contacts with the same name only, it won’t find other occurrences where a name has changed, or a place of business has changed. In that case, you’ll want to manually combine the contacts yourself using the first method outlined above.

Re-Sync to iCloud & iPhone

Assuming iCloud is set up to be the same on the Mac and iPhone, you should find the changes made in for OS X appearing on the iPhone automatically and fairly quickly. For that to happen, on the iPhone (or other iOS device), you must have iCloud syncing enabled for Contacts, it’s on by default but you can confirm easily:

  • Open “Settings” and go to iCloud, make sure “Contacts” is set to ON

If you don’t see the changes within a few minutes and don’t want to wait, you can always sync manually through iTunes as well.