FaceTime and iMessage both help people stay in touch with their friends and family. The phone number of the email address linked to the account is used to find the user. If you want to get rid of a certain phone number for any reason, you can do so in Settings.
How to remove a phone number from Apple iPhone iMessage and FaceTime
Step 1: On your Apple iPhone, open the Settings app.
Step 2: When you open settings, scroll down or search for “messages.”Tap the “Messages” option.
Step 3: On the settings page for Messages, tap “Send & Receive.”
Step 4: After that, tap the phone number you want to get rid of and then tap “Remove.”
All done. If you follow this step-by-step guide, you can remove your phone number from your Apple ID so that you can’t use it for iMessage or FaceTime anymore. You can also do this by going to the FaceTime app instead of the Settings app. Once you’ve registered your phone number, you can still use FaceTime to make and receive regular calls and SMS.