The Senate has passed a bill legalizing phone unlocking, following a favorable House vote on a companion bill this spring. The Unlocking Consumer Choice and Wireless Competition Act, brought by Senator Patrick Leahy (D-VT), reinstates a rule allowing consumers to "unlock" their cellphones for use on a different network, whether on their own or using a professional unlocking service. The passage comes over a year after President Barack Obama came out in support of the policy, and about six months after phone companies agreed to adopt clear unlocking practices in the absence of a law.

When purchased, most phones are usable only on a specific network. Though carriers can choose to remove this restriction after the buyer's contract is up, consumers who want to unlock their own phones operate on shaky legal ground. Anti-DRM-cracking sections in the Digital Millennium Copyright Act make it potentially illegal to modify a phone's firmware to work on another network. The Library of Congress codifies exceptions to these rules every three years, and it decided to remove the phone-unlocking exemption in late 2012. After Obama's statement, a number of bills were introduced to address the issue.

The phone companies' agreement in late 2013, brokered by the FCC, made it easier for customers to get a phone unlocked. But supporters of the unlocking bill have said that consumers shouldn't need carrier approval to modify a phone that they own, and that people who receive phones secondhand or otherwise operate outside the normal two-year contract process could fall through the cracks. Leahy's bill doesn't permanently legalize phone unlocking, but it requires the Library of Congress to put an exemption back in place and consider whether to extend it when it comes up for renewal again. It also modifies the rule slightly: in addition to letting consumers unlock a phone themselves, they can direct a third party (like a company or technician) to do it. Consumer group Public Knowledge praised the change, saying that unlocking is "something many cannot do without technical assistance."

This bill is very similar to the House version passed in February, but one provision has been removed: a ban on unlocking phones "for the purpose of bulk resale." The rule is meant to protect companies like Tracfone, which sell heavily subsidized prepaid phones. But it was decried by groups that believe the DMCA shouldn't govern phone unlocking at all — Public Knowledge said it "further confused the issues of copyright law and business models." Leahy says he is coordinating with House bill author Bob Goodlatte (R-VA) to ensure that the Senate's version can be approved quickly and signed into law by President Obama.