Last week AT&T announced that it would allow the out-of-contract customers to unlock their iPhones and use it on another carrier. It was indeed good news for those users who travel overseas, since an unlocked iPhone is ideal for them, allowing them to use a cheaper SIM card from a local GSM wireless carrier rather than paying for expensive service from AT&T.
The carrier issued a statement saying that the only requirements are that a customer's account must be in good standing, their device cannot be associated with a current and active term commitment on an AT&T customer account, and they need to have fulfilled their contract term, upgraded under one of our upgrade policies or paid an early termination fee.
To get their iPhones unlocked, the users were first required to place a call to AT&T or have an online chat with them to start the process. After collecting basic information from the users, AT&T takes some time (72 hours to 2 weeks) to verify whether the requests are indeed eligible to initiate the unlocking the process.
Those users, who care about their jailbreak, may not be able to unlock their iPhone without losing the untethered jailbreak on their device. But for their rescue, there is a way out, thanks to RedSn0w.
However, the same method won't work on the iPhone 4S since RedSn0w doesn't support A5 jailbreak yet. As Jailbreak Untethered noted, the only option you have is to rely on SAM (Subscriber Artificial Module) to do the job.
SAM, created by @sbingner, allows users to deactivate the iPhone 4S officially without using a stock SIM. The users who have jailbroken their iPhone 4S using Absinthe, below are the steps to follow:
Users must note that using the method to update devices is their own decision. IBTimes will not be held responsible for any consequence.
Step 1: Head to your Cydia Store and add repo http://repo.bingner.com and tap install SAM.
Step 2: Go to your settings, select SAM then deactivate iPhone
Step 3: First, SAM will deactivate your iPhone 4S. Then when you connect your iPhone back to iTunes, it will activate your iPhone and your device will get unlocked in an official way.
[Source: Jailbreak Untethered]