Early GSM iPhone 4S adopters may be happy to hear that Twitter user xoicos has found a way to unlock the new handset using a bug in iOS 5. Of course, we know that Apple sells unlocked phones outright, but they are considerably more expensive.

Unlocking a device means that you are be able to activate it on other wireless carriers outside of the one you purchased the phone on. Initially, unlocking the iPhone required complexed baseband tweaking, but now it could be as easy as following these steps…

OS X Daily claims that several users have reported success with this unlock method, but it does warn readers to follow the guide at their own risk. We haven’t been able to confirm its safety or success either, so we are going to issue the same warning.

This tutorial describes how to unlock an AT&T iPhone 4S to work on T-Mobile’s network, so results with other carriers may vary. You’ll need a GSM iPhone 4S, and both an AT&T and T-Mobile SIM card (or one from a compatible GSM carrier).

Step 1. Insert your AT&T SIM card. Dial 611 for customer service, and once it starts ringing, hang up.

 Step 2. Turn on your iPhone’s Airplane mode, take out the AT&T SIM card, and replace it with a T-Mobile SIM.

 Step 3. Make sure Wi-Fi is off, and clear any remembered networks to ensure it doesn’t auto-connect later.

 Step 4. Turn off Airplane mode. The handset will search for a network, and the Activation Required screen will popup.

 Step 5. Once you notice the device has found an EDGE network (E symbol), wait about 30 seconds and turn off the phone.

 Step 6. Power the handset back on, and you should see the same Activation Required screen.

 Step 7. Once you notice you have 1 bar of signal, tap on the Use Cellular Connection option. Then eject the SIM card.

 Step 8. The Activation Required screen should pop up again. Re-insert the T-Mobile SIM card, and you should be unlocked.”

It’s worth noting that some users had to repeat this process multiple times for it to work. We’ll keep you updated on our findings once we can test this out for ourselves.

Did this guide work for you?

Update: This hack seems to only create a temporary unlock. Here’s ic0edx‘s comment: “Just to clear things up for everyone. This is a temporary unlock, once the carrier refreshes the TMSI the iPhone 4S will lock back up again.”