Unlike duplicate music files, iOS 7 doesn't give you the option to delete tones on the iPhone itself. If you have duplicate tones, the only way to delete them is by using iTunes. Deleting duplicate tones in your iTunes library and then syncing the iPhone should almost always get rid of the duplicates on your iPhone. If this doesn't work, you may have to remove all of your custom ringtones from the iPhone, sync, delete the duplicates in your iTunes library again, before selecting the ones you want and syncing your iPhone a third and final time.

Step 1

Launch iTunes on your computer. If iTunes prompts you to install an update, do this before proceeding. Click the "Library" button in the upper left corner and select "Tones." This displays all of your ringtones.

Step 2

Look for any duplicate names. As with music files, if two tones have the same name, they aren't necessarily duplicates. For example, if the time for each tone isn't the same, they are not duplicate files. Double-click a tone to listen to it on your computer. Once you are certain there are duplicate tones, delete the duplicates.

Step 3

Connect the iPhone to your computer using its USB cable. Click the "iPhone" button when it appears in the upper right corner and then click the "Tones" tab in the top center of the window.

Step 4

Click the "Sync Tones" option if it isn't already selected. The tones on the iPhone appear on the screen. At this point, there should be no duplicates listed and you can select the "All Tones" option if you want. If duplicates do appear on this screen, click the "Selected Tones" option and then select only the tones you want to appear on the iPhone. Click "Apply" and then click "Sync."

Step 5

Unlock the iPhone's screen, select "Settings," then "Tones" to confirm that the duplicates are gone. If duplicates still appear, deselect all of the tones in iTunes and sync the iPhone again. This removes all of the tones from the iPhone. Repeat the entire process, first deleting all duplicates in your iTunes library, then selecting the tones you want in the iPhone and syncing one last time. Any remaining duplicates are permanently deleted from both iTunes and the iPhone.