But there's one big catch to qualify - you have to be a current AT&T customer with a completed contract. For example, you originally bought an iPhone 3GS in 2009 and upgraded to the 4 or 4S on your own without renewing your contract.
The move makes business sense for AT&T. With the 5-year deal signed with Apple expiring soon, the company is looking to differentiate itself from competitors. Even though Verizon and Sprint carry the iPhone 4S, both still lock it to their network and charge roaming fees when travelling abroad. Additionally, the iPhone does not support T-Mobile's 3G network, making it unlikely that unlocked customers will leave for that competitor.
