If you use FaceTime fairly consistently and have more than one email address or phone number, you may have added those addresses to your FaceTime account. If you'd like to be consistent across all your devices, you can set the caller ID to show a specific email address or phone number each time you make a FaceTime call so it's consistent for all the people you contact.
Follow along and we'll show you how.
Launch the Settings app from the Home screen of your iPhone or iPad.
Tap on FaceTime.
Scroll down towards the bottom and under the Caller ID section, choose the number or email you'd like to set your caller ID as.
That's all there is to it. FaceTime will now use that number or email as the caller ID for that device.