Hi @Josh98. @andewhite is correct here. Just to add to this, what happens when you try the following steps. Does the correct mobile number show up in your iPhone settings?
- Check your software is up to date.
- Update the correct number
* Go to Settings > Phone > My Number.
* Replace the temporary number you find there with your own number. Use +44 instead of the first 0.
* Then tap Save.
- Reset iMessage settings. Your iMessage settings won't reset themselves during porting - the temporary number will likely still be in your new iPhone.
- Input your ported number into your new iPhone:
* Go to Settings
* Tap on Messages
* Tap iMessage ON
* Scroll down to Send & Receive number
* Replace the temporary number with your ported number
* Then tap Save.
- Toggle off imessage then reboot and then toggle on after 3-4 minutes and reboot the device.
- Go to Setting -> Messages -> Click send & receive -> 'You can receive imessage to and Reply from'
See if the correct number is displayed under start new conversations from and also tick only on either your Mobile number or your email address to send iMessage.
After doing all this the device and then try
-Lauren