One of the most important sets of information on your iPhone is your contacts. Many users have been faced with an issue when trying to sync their iPhone contacts with their computers. If you have entered your contact information on your iPhone first (not on your computer) and would now like to retrieve those contacts for your computer, this post is for you. Please read the entire post before attempting:To Sync your iPhone contacts from your iPhone to your computer:

1. Be sure to have a backup of any contacts (export a vCard or .csv file from your contact management program) you may have on your computer that you want to keep.

2. Plug your iPhone into your computer and launch iTunes. iTunes automatically creates a backup of your iPhone (including contacts).

3. Once your iPhone is backed up, uncheck the “Automatically sync when this iPhone is connected” box.

4. Under the “Info” tab, check which contacts you would like to sync.

5. Click the “Sync” button in the bottom right corner of the iTunes window.

6. iTunes will see that you are changing the contacts information for more than 5 percent of your data and ask if you would like to replace the data on the phone, replace the data on the computer, or merge all data.

   Replacing the data on the iPhone will erase everything you have entered on your phone and only show you what you had on your computer.

   Replacing the data on the computer will erase everything you have entered on your computer and only show you what you had on your iPhone.

   Merging the data will combine the data from each– a process that can create duplicate contacts.

7. Choose the appropriate action for your situation.

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Source: MacFixIt.com