The nation’s second-largest carrier, AT&T, is beginning to unlock in-contract iPhones for the United States military personnel deployed abroad, a new report claimed Monday. As you know, AT&T is now unlocking out-of-contract iPhones for its regular subscribers.

The unexpected policy change has been instituted following unconfirmed reports last week that some disgruntled customers who had complained about the situation to Apple CEO Tim Cook via email saw their handsets unlocked.

As a result, AT&T subscribers can now slip in a SIM card from another wireless operator and use their 3G GSM iPhones with compatible cellular networks overseas and in the United States, such as T-Mobile USA (which welcomed the change)…

According to unnamed sources who spoke with MacRumors:

In addition to unlocking phones for off-contract customers, AT&T is also quietly unlocking iPhones for U.S. service members still under contract with the carrier.

The publication stressed that federal law mandates that carriers suspend service without penalty for deployed military personnel “upon presentation of their military orders”.

Though AT&T is not required to unlock the handsets, they are nonetheless choosing to do so on their own, the report has it.

If you are considering unlocking your AT&T iPhone, we have a handy survival guide to help find your way around AT&T’s online technical support chat system.