iOS: Deactivating iMessage
If you experience any of these symptoms, you may want to deactivate iMessage:
- You can't receive SMS on your non-Apple device when another person sends them using an iPhone.
- You can't send SMS to a non-Apple device because they send as an iMessage.
If you experienced the symptoms above, your cellular phone number may still be registered with iMessage. When you turn iMessage on with your iPhone, iMessage registers your cellular telephone number.
To deregister your phone number, tap Settings > Messages and turn iMessage off.
If you can't deactivate iMessage after you perform the steps above or you can't access the iPhone, please contact Apple Support.