AT&T announced the change in policy in a statement issued on Friday. It takes effect in just two days, on April 8.
"Beginning Sunday, April 8, we will offer qualifying customers the ability to unlock their AT&T iPhones," the statement reads. "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."
Previously, customers who finished the terms of their two-year contract with AT&T had an iPhone that could not be unlocked through official avenues. That meant even though they were free to leave for another carrier, they could not bring their iPhone with them.
Apple's latest handset, the iPhone 4S, is a "world phone" capable of connecting to both GSM networks like AT&T, as well as CDMA carriers like Verizon. If unlocked, it can also be used to roam worldwide on GSM networks. That means customers who unlock their iPhone from AT&T will not be able to use it with Verizon, even if it is the iPhone 4S.
The iPhone 4S can also be purchased unlocked and contract-free direct from Apple. It is available priced at $649 for the 16-gigabyte model, $749 for 32 gigabytes, and $849 for 64 gigabytes.
Apple's website alerts people that the unlocked iPhone only works with supported GSM networks, like AT&T in the U.S. The iPhone can also be used with T-Mobile in the U.S. for voice and EDGE data connections, but it is not compatible with T-Mobile's faster 3G network.
"When you travel internationally, you can also use a micro-SIM card from a local GSM carrier," Apple's site reads. "The unlocked iPhone will not work with CDMA carriers such as Verizon Wireless or Sprint."