AT&T, Verizon Wireless, Sprint, T-Mobile, and US Cellular have "voluntarily" committed to unlocking customers' cell phones once their contracts have been paid off. The wireless carriers will notify customers when their devices are eligible to be unlocked, "or automatically unlock devices remotely, for free," the Federal Communications Commission (FCC) said today.

While the agreement was described as voluntary, FCC Chairman Tom Wheeler had told the carriers he would pursue regulation if they didn't comply with his terms. A recent ruling by the Librarian of Congress meant that a consumer unlocking his or her own phone would be violating the Digital Millennium Copyright Act's anti-circumvention provisions. Today's agreement should sidestep that by putting the onus to unlock on the carrier, although it doesn't help consumers who are still under contract.

Unlocking allows a phone to be used on any compatible network, regardless of carrier. While carriers are often willing to unlock phones and sometimes ship them unlocked even at the beginning of a contract, policies have varied by carrier. Today's news will make the unlocking process similar across all major US carriers.

The CTIA wireless association confirmed in a letter to the FCC that the five carriers will adopt the "voluntary industry principles" and that they will be applied both to mobile phones and cellular-enabled tablets. Within three months, each carrier will implement three out of the six standards specified in the agreement. Within 12 months, the carriers must implement all six. The clock apparently starts ticking only after the agreement becomes part of CTIA's official code.

The six provisions are as follows:

1. Disclosure: Each carrier will post on its website its clear, concise, and readily accessible policy on postpaid and prepaid mobile wireless device unlocking. 2. Postpaid unlocking policy. Carriers, upon request, will unlock mobile wireless devices or provide the necessary information to unlock their devices for their customers and former customers in good standing and individual owners of eligible devices after the fulfillment of the applicable postpaid service contract, device financing plan or payment of an applicable early termination fee. 3. Prepaid unlocking policy. Carriers, upon request, will unlock prepaid mobile wireless devices no later than one year after initial activation, consistent with reasonable time, payment, or usage requirements. 4. Notice. Carriers that lock devices will clearly notify customers that their devices are eligible for unlocking at the time when their devices are eligible for unlocking or automatically unlock devices remotely when devices are eligible for unlocking, without additional fee. Carriers reserve the right to charge non-customers/non-former customers a reasonable fee for unlocking requests. Notice to prepaid customers may occur at point of sale, at the time of eligibility, or through a clear and concise statement of the policy on the carrier's website. 5. Response time. Within two business days after receiving a request, carriers will unlock eligible mobile wireless devices or initiate a request of the OEM to unlock the eligible device, or provide an explanation of why the device does not qualify for unlocking, or why the carrier reasonably needs additional time to process the request. 6. Deployed personnel unlocking policy. Carriers will unlock mobile wireless devices for deployed military personnel who are customers in good standing upon provision of deployment papers. Consumers will have access to clear, concise, and readily available policies about unlocking their devices.

Carriers can decline an unlock request if they think it's a fraudulent request or that the device is stolen.