1. Turn off iMessage: The first thing you need to do is to turn OFF iMessage. To do this:
- Go to Settings
- Scroll down and tap on Messages
- Switch OFF iMessage
The reason you’re turning OFF iMessage is so as to re-send an SMS activation for iMessage which tells Apple your new number.
2. Power down and wait: Usually, people jump to step #3 from here and it works. But for a good measure, power down your device and wait 5-10 mins before proceeding to the next step.
3. Edit your phone number detail: Once you’ve rebooted the phone after step #3, check if Phone number details on your phone reflect the new number. They usually do but just to be sure.Go to Settings → Phone and make sure “My Number” reflects your new number. If not, edit this.1Also, make sure the time & date settings in your iPhone are set to automatic. (they can be found in Settings → General → Date & Time)
4. Turn On iMessage again: Now, just head over to the Messages settings and turn on iMessage.
- This should usually send an SMS to Apple’s servers. (it happens in the background).
- iMessage should be activated now for the new number. How to check this? Next step.
5. Check ‘Send & Receive As’
In the “Send & Receive as” field, you should see your new number ticked and grayed out. If this field is empty or has your old number, it means the process did not go as expected and you’ll need to repeat it.
If it shows your new number, you’re set.