Shortly after 9to5Mac broke a story about an AT&T customer resorting to asking Tim Cook for help unlocking his iPhone, AT&T has decided to start unlocking iPhones for “qualifying customers.”

The story from a couple weeks ago dealt with an AT&T customer who had been reassigned to Canada for work but wanted to continue using the iPhone 3GS he had already purchased from AT&T. AT&T refused to unlock the device so the customer sent a letter to Tim Cook as a last resort. Tim Cook took care of the problem and the man’s iPhone was unlocked.

Now AT&T, as of April 8th, will be offering the ability to unlock iPhones to customers who are in good standing and are either off contract or pay a termination fee.

According to Ars Technica, users have been reporting that to unlock the phone they must first initiate a call with AT&T, get approved for being unlocked, then go through a system with Apple receiving a code via email, and a backup and restore through iTunes. At first, it seemed that the process could be done completely online (using AT&T’s Wireless Support Chat) until users started reporting that a call to AT&T was needed to start the process.

This adds a greater resale value to iPhones that were purchased through AT&T. It’s now possible to sell an old, unlocked AT&T iPhone without going through jail-breaking methods to unlock the phone.

Check out the official statement by AT&T at Engadget.