How to use T-Mobile sim card on an AT&T (and potentially other) iPhone 4S

November 20, 2011

Here’s an unconfirmed method of using an AT&T iphone on T-Mobile network. When I say unconfirmed, it means I didn’t get the chance to test it myself. However, there’s a bit of skeptisism rising around the tutorial on youtube whether this method actually works. Some people are saying it worked, some are saying it didn’t work at all and some are saying it only worked for a couple of minute. My suggestion would be giving a shot without any expectation. This method was only applied on US carrier AT&T subsidized iPhone 4S white, it’s not clear yet whether or not the same method is going to work in other countries. Here’s a written step by step version:

Insert original carrier AT&T SIM card
Dial 611 for AT&T customer service hotline and drop the call
Turn on Airplane Mode
Take out AT&T SIM card
Insert T-Mobile SIM card
Make sure WiFi is off ( also tap on ‘Forget this Network” to make sure it doesn’t connect automatically later)
Switch off Airplane Mode and iPhone will search for network. This is followed by the Apple splash screen appearing.
Activation Required will be displayed on the screen
EDGE network will activate automatically — notice the ‘E’ on the top left corner of the screen
Wait for about 20-30 seconds and turn off the phone
Turn on iPhone and the same Activation Required screen will be displayed
When you see one signal bar, tap on Use Cellular Connection
Eject SIM card
Activation Required screen will be displayed the second time
Insert SIM card
Check if it worked.

P.S. Here’s a another video from the same user answering some question that popped up on the tutorial comment thread. http://www.youtube.com/watch?v=r6zZLvaQI4g