Apple® iPhone® 4s - Turn International CDMA On / Off
Postpaid customers: To get specific info on using your service while traveling internationally, visit our International Trip Planner, enter your info then click 'Sign in' for a personalized solution or 'Get Started' if you don't want to sign in.
From the Home screen, navigate: Settings > Cellular > Cellular Data Options.
Tap the Voice Roaming switch to turn on or off .
Voice Roaming must be on for the Data Roaming and International CDMA options to be available.
To enable Data Roaming, tap the Data Roaming switch to turn on or off.
Tap the International CDMA switch to turn on or off.
Turning off International CDMA while in another country may improve poor messaging or data performance.