We have been looking ultrasn0w unlock which seems to be very simple in the past. Afterwards Gevey sim unlock also became famous for unlocking iPhone 4 but now we have a great news for those who want their iPhone 4S carrier unlocked which is now possible for iPhone 4S with baseband 1.0.11 carrier network without any software or hardware modification.

Micheal Capozzi found an iOS 5.x bug which led him to unlock iPhone 4S running on AT & T to T-Mobile. The step by step guide for unlocking your iPhone 4S is as follows:

Step 1:  First of all Insert original carrier AT&T SIM into your iPhone 4S

Step 2: Make a Call to AT&T’s Customer Service Number which is 611 and drop the call which will activate the Airplane mode.

Step 3: Remove your AT&T SIM and replace it with T-Mobile one.

Step 4: Ensure that WiFi is off by taping on “Forget this Network” so that it doesn’t connect automatically.

Step 5:  Deactivate youe Airplane mode. Once done iPhone will start searching for the network which will be followed by the Apple Activation Screen.

Step 6:  EDGE network will have been activated and you will find the E on the top left corner of the screen.

Step 7:  Wait for 20-30 seconds and switch your phone off.

Step 8:  Turn your iPhone ON back again and Activation Required Screen will be displayed.

Step 9:  When you find the Signal Bar, tap on Use Cellular Connection

Step 10:  Eject your SIM and Activation Screen will appear for the Second/Third time.

Step 11:  Re-Insert your SIM and your iPhone 4S will be unlocked.

Video Guide: