AT&T is now unlocking iPhones, which is awesome, but also a hassle if you don't live near an AT&T store. So here's a quick how-to on unlocking your phone without ever leaving your house.
You need to meet three criteria to qualify to unlock your phone: Your account can't be in a longterm contract, your phone can't be associated with an active-term contract, and your account must be in good standing. That's it. You can also pay an early termination fee, if you're still under contract with AT&T and just want out now.
First, get your phone's IMEI (International Mobile Equipment Identity) number. It's under Settings, General, About. Now log into AT&T's Wireless Support Chat, and request your unlock. And that's all from AT&T. For anything else, it ships you off to Apple Support.
The bottleneck is waiting for Apple to acknowledge AT&T's request and send you your unlock code by email. This can take "up to 72 hours," but Ars reports that users are seeing codes in as little as one hour. Once you've got it, you'll be prompted to connect your phone to your computer and use iTunes to perform a backup restore. And there you go, unlocked iPhone.
Just for redundancy's sake, we'd like to remind you that you only really need to unlock your phone if you're switching carriers, or perhaps moving (or selling your phone) internationally. It's not quite like the old days where unlocking your phone would strip you of loads of updates and features, but you gain no tangible benefit if you're just staying on AT&T. [Ars Technica]