Hey there,
- Make sure you're using the latest iOS device.
- Make sure you've correctly followed the iPhone steps to set up your phone number. You should be using the same Apple ID on all of your devices.
- In the "You can be reached" section of Messages and FaceTime settings, make sure there are ticks next to your phone number and Apple ID:
If your phone number is unticked and you can't select it, or you're experiencing a different issue, follow these steps:
On your iPhone, iPad and iPod touch:
- Go to Settings > Messages > Send & Receive. Tap your Apple ID, then tap Sign Out.
- Go to Settings > FaceTime. Tap your Apple ID, then tap Sign Out.
On your iPhone:
- Go back to Settings > Messages and make sure iMessage is turned on.
- Tap Send & Receive, then choose "Use your Apple ID for iMessage" and sign in with your Apple ID.
Using the same Apple ID, sign back in to Messages and FaceTime on your other devices.
If you still need help, change your Apple ID password and repeat the setup steps. If that doesn't work, contact Apple Support.