International iPhone settings

[MahiMahi524]

Hi everyone,

I did some extensive searching, and I just wanted to verify when I travel internationally from the US the features I want to use with the settings I plan on using on my unlocked 4S:

1. If I remove the US SIM, I can use Wifi (including iMessage) and GPS without incurring any international charges from AT&T. I will disable sending iMessage as SMS. I already have local maps downloaded onto a GPS app so won't need data plan to download maps as I go.

2. If I get a temporary SIM in South Africa, I can continue to use iMessage under my US phone number as long as I don't disable and re-enable iMessage. (That way it does not re-register iMessage with my temporary South African phone number.) That seems to mean iMessage will work with my US number at least under Wifi.

3. My question is, can I still send iMessages under my US phone number when sending with cellular data via the South African SIM? (Assuming I don't turn off/on iMessages.)

Any additional info is appreciated. Please let me know if this is all correct. Thanks!

 

[Max(IT)]

Actually this is a very good question and I don't have the answer.
Traveling a lot for business I can say:

1- correct. iMessage will work under wifi but you don't really need to remove the US SIM as long as you have Settings - General - Cellular - Data Roaming Off, and Messages - Send as SMS Off;

2- correct. With same settings as above.

3- I don't really know and I'm afraid that only way to know it is to try it.

 

[MahiMahi524]

Actually this is a very good question and I don't have the answer.
Traveling a lot for business I can say:

1- correct. iMessage will work under wifi but you don't really need to remove the US SIM as long as you have Settings - General - Cellular - Data Roaming Off, and Messages - Send as SMS Off;

2- correct. With same settings as above.

3- I don't really know and I'm afraid that only way to know it is to try it.

Thanks for the reply. The problem with not removing the SIM is if someone calls and gets forwarded to voicemail (even with call-forwarding enabled), I will get charged international voice rates. There is no way to disable cellular voice except with airplane mode, which also disables GPS (which I am using). The charges have apparently been reported in some people's experiences, and perhaps a change in AT&T policy from several years ago. I verified with AT&T that even with call forwarding enabled, because the call gets routed to my phone in South Africa, and then re-routed back to the US for voicemail, I would get charged, possibly double. They said the only way to avoid this is to remove the SIM or to disable the line temporarily.

Would appreciate anyone else's experience with #3.

 

[Max(IT)]

Strange behavior on your operator part.
With Vodafone (at least with Vodafone Italy) if you disable call forwarding to voicemail in Italy, when you are abroad incoming call are not forwarded and you're not charged for anything.
Caller will just receive a notification that you're not available at the time WITHOUT the possibility to leave a message.