Swap SIM for number portability
To remove MSISDN number for iMessage and FaceTime and keep the old number which has been inported for iMessage and FaceTime
iPhone 12 Pro Max
Apple Intelligence is now available on iPhone, iPad, and Mac!
To remove MSISDN number for iMessage and FaceTime and keep the old number which has been inported for iMessage and FaceTime
iPhone 12 Pro Max
Simply activate iMessage on your Old SIM
To activate iMessage and FaceTime using your Phone number
First, check to know whether you have an SMS plan enabled at least for One SMS*** with your carrier. Contact your Carrier (Cellular Service Provider) the agency that issued the SIM to you
If your iPhone is used with a carrier not found in the wireless carrier articles, make sure you can send and receive international SMS. (One SMS*** Only)
If you can't turn on or sign in to iMessage or FaceTime - Apple ...
*** You may not have an SMS plan enabled by your carrier for the SIM/eSIM that you use on your device. Apple Inc does not provide SMS services.
Simply activate iMessage on your Old SIM
To activate iMessage and FaceTime using your Phone number
First, check to know whether you have an SMS plan enabled at least for One SMS*** with your carrier. Contact your Carrier (Cellular Service Provider) the agency that issued the SIM to you
If your iPhone is used with a carrier not found in the wireless carrier articles, make sure you can send and receive international SMS. (One SMS*** Only)
If you can't turn on or sign in to iMessage or FaceTime - Apple ...
*** You may not have an SMS plan enabled by your carrier for the SIM/eSIM that you use on your device. Apple Inc does not provide SMS services.
Why do you want to de-register? de-register is only done when you want to use the same SIM on a non-iOS device.
If you still have an iPhone and want to stop iMessages on that number simply go to
Settings > Messages > iMessage [Disable]
Settings > FaceTime > FaceTime [Disable]
That's it.
Probably you are wanting to remove this old number from Apple ID. If that is so watch the GIF below
Resolved by signing out if Apple and setting the number I want and then signing in
Swap SIM for number portability