I’m having problems with iMessage after transferring my number
If you’re an Apple user and your iMessages aren't working after porting, it's usually because you need to amend your settings.
Here's what you need to do:
Go to ‘Phone’ and then ‘My number’.
Manually change the number in this field.
Turn your phone on and off again to reboot the settings.
You can also try the following:
Settings > General > Date & Time (make sure the time zone is set correctly)
Go to Settings > Messages and turn off iMessage
Go to Settings > FaceTime and turn off FaceTime
Restart your device
Turn iMessage and FaceTime back on.
If you've tried all the above and your iMessages are still not activated after 24 hours have passed after the transfer, please follow these steps:
Make sure your device has the latest version of iOS
You might experience intermittent service on the day (e.g. temporarily unable to make calls or use mobile data), which is a normal part of moving your number.
If your number hasn’t moved over by midnight, restart your phone with the SIM in it. If you are still having issues, you can.