Before you remove the SIM card from your iPhone
Turn iMessage off before you remove the SIM card from your iPhone. Otherwise, your SMS/MMS messages could continue going to your old iPhone instead of to your new phone.
Turn off iMessage
- On your iPhone, go to Settings.
- Tap Messages.
- Set iMessage to Off.
Turn off FaceTime
- On your iPhone, go to Settings.
- Tap Facetime.
- Set Facetime to Off.
Already removed the SIM card from your iPhone
If you no longer have your old iPhone or already removed the SIM card, request that Apple deregister your phone number with iMessage.