US consumers will be allowed to unlock their cellphones and move them to a new carrier under a measure adopted Friday to fix a perceived glitch in copyright law.
The House of Representatives approved the bill unanimously one week after it passed the Senate, sending the legislation to President Barack Obama for his signature.
Under the Unlocking Consumer Choice and Wireless Competition Act, users will be able to unlock handsets and switch carriers without fear of prosecution, provided any contract terms from the original sale are honored.
The law became necessary after the Librarian of Congress ruled that those who circumvent the software locking a mobile phone to a single carrier are violating the Digital Millennium Copyright Act, enacted to thwart piracy.
Obama said in a statement he would sign the bill.
"The bill Congress passed today is another step toward giving ordinary Americans more flexibility and choice, so that they can find a cell phone carrier that meets their needs and their budget," Obama said.
The copyright ruling generated a flurry of protests from civil liberties and digital rights activists last year.
Unlocking has been possible through requests to carriers, but those who did it themselves -- a practice sometimes called "jailbreaking" -- would be subject to prosecution.
More than 100,000 people signed an online petition last year asking the White House to support a revision of the law.
Senator Patrick Leahy, one of the sponsors of the bipartisan bill, said it "puts consumers first, promotes competition in the wireless phone marketplace, and encourages continued use of existing devices."
Laura Moy at the consumer group Public Knowledge said the measure "will have other positive effects."
"It will make it easier for consumers to switch from one provider to another, improving competition in the wireless market," she said.
"It will improve the availability of free and low-cost secondhand phones for consumers who cannot afford to purchase new devices; and it will keep millions of devices out of landfills."