The Republic of Chile has announced that all cellphones sold within the country starting last Monday, January 2nd, must be unlocked for use on any carrier. Chile's telecoms regulator, Subtel, revealed its plans over Twitter on Monday, which are said to be part of an effort to make cellphone numbers more portable in the country — number portability officially kicks off on the 16th. Existing devices, purchased prior to January 2nd, will be unlocked free of charge thanks to an online site that requires IMEI and device information to process the unlock.

Chile joins a small number of countries who have outlawed SIM-locked phones. Singapore's national telecoms regulator was one of the first to forbid network locking and contract bundling, while Israel also passed a law in late 2010 to ban carriers from locking devices. There are no laws in the US or UK to prevent SIM-locking by carriers, but most will simply unlock phones at the end of a contract. The lack of legislation worldwide has led to the popularity of handset jailbreaking and rooting to enable unofficial carrier unlocks, a process that Chileans won't have to worry about anymore.

Update: We'd originally reported that the mandatory unlocking would begin on January 16th, but the editorial director of Wayerless — one of the sites originally reporting the news — wrote in to tell us that the mandate actually began on the 2nd. The 16th, meanwhile, will be when number portability between carriers becomes available.