You may be able to roam on GSM networks, if you have a CDMA account and you have an
iPhone 4s or later with a SIM card installed. While roaming on a GSM network, iPhone has access
to GSM network features. Charges may apply. Contact your carrier for more information.
Set network options. Go to Settings > Cellular to:
Turn data roaming on or off
Turn cellular data on or off
Turn voice roaming on or off (CDMA)
Use GSM networks abroad (CDMA)
on page 151.
Turn off cellular services. Go to Settings, turn on Airplane Mode, then tap Wi-Fi and turn it on.
Incoming phone calls are sent to voicemail. To resume cellular service, turn Airplane Mode off.
Make calls to your contacts and favorites while traveling abroad. (GSM) Go to Settings > Phone
and turn on Dial Assist. Dial Assist automatically adds the prefix or country code for calls to the U.S.
Select a carrier network. Go to Settings > Carrier. This setting appears on GSM networks when
you're outside your carrier's network, and other local carrier data networks are available to use
for your phone calls, visual voicemail, and cellular network Internet connections. You can make
calls only on carriers that have a roaming agreement with your carrier. Additional fees may apply.
Roaming charges may be billed to you by the other carrier, through your carrier.
Get voicemail when visual voicemail isn't available. Dial your own number (with CDMA, add #
after your number), or touch and hold "1" on the numeric keypad.
Go to Settings > Phone to:
See the phone number for your iPhone
Change the default text message replies for incoming calls
Turn call forwarding, call waiting, and caller ID on or off (GSM)
Turn TTY on or off
Change your voicemail password (GSM)
Require a PIN to unlock your SIM when you turn iPhone on (required by some carriers)
Go to Settings > Sounds to:
Set ringtones and volume
Set vibration options
Set the sound for new voicemail
Once you select a network, iPhone uses only that network. If the network is unavailable, "No
service" appears on iPhone.