Fortunately, Apple has made it possible for you to remove phone numbers from your FaceTime account and use email addresses instead. The following steps show you how it's done.
- Launch the Settings app on your iPhone or iPad.
- Scroll down and tap FaceTime.
- If you're not signed into FaceTime with your Apple ID, tap Use your Apple ID for FaceTime, then tap Sign In, or tap Use Other Apple ID and enter the credentials that you want to use.
- Tap on the checkmark to the left of any number that you want to disassociate with FaceTime.
- Tap the email address(es) that you want to use with FaceTime instead.
To re-enable any numbers or addresses, simply tap the number or address to add the checkmark back. Note that if a number is greyed out in the list, this is the number of the phone that you are currently using and it cannot be de-linked from FaceTime on this device without swapping the SIM card.