How to Unlock iPhone 4S, 4, 3GS without Jailbreak or Gevey SIM
Step 1: Insert original carrier AT&T SIM card
Step 2: Dial 611 for AT&T customer service hotline and drop the call
Step 3: Turn on Airplane Mode
Step 4: Take out AT&T SIM card
Step 5: Insert T-Mobile SIM card
Step 6: Make sure WiFi is off ( also tap on ‘Forget this Network” to make sure it doesn’t connect automatically later)
Step 7: Switch off Airplane Mode and iPhone will search for network. This is followed by the Apple splash screen appearing.
Step 8: Activation Required will be displayed on the screen
Step 9: EDGE network will activate automatically – notice the ‘E’ on the top left corner of the screen
Step 10: Wait for about 20-30 seconds and turn off the phone
Step 11: Turn on iPhone and the same Activation Required screen will be displayed
Step 12: When you see one signal bar, tap on Use Cellular Connection
Step 13: Eject SIM card
Step 14: Activation Required screen will be displayed the second time
Step 15: Insert SIM card - Unlocked!