SIM lock

(redirected from Cellphone unlocking)
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SIM lock

(Subscriber Identity Module lock) A function in GSM cellphones that restricts the phone's use to a particular cellular carrier (a particular SIM card). SIM locks are used to ensure subscribers finish their service contracts when the phones are heavily subsidized by the carrier. SIM locked phones may be unlocked by entering a code.

Apple's iPhone brought the SIM lock into public view because of its original exclusivity in the U.S. with AT&T. However, iPhones were readily "unlocked" by hackers both in and outside the U.S., not only to use a different carrier, but to customize their appearance and download applications even before Apple debuted its App Store. In addition, Apple allowed the GSM iPhone to be sold without the SIM lock in Australia, Taiwan, Hong Kong and other regions where locked phones were either prohibited or a recipe for marketing failure. See SIM card and iPhone jailbreaking.
References in periodicals archive ?
NTIA presses FCC to undo ruling on cellphone unlocking A Commerce Department adviser to President Barack Obama has pushed the Federal Communications Commission to eliminate cellphone unlocking bans when consumers change providers.
While we have not yet reviewed NTIA's petition on cellphone unlocking filed today, CTIA welcomes the opportunity to work with the Administration and the FCC to highlight the wealth of device options that exist for U.
To help further enhance the customer experience, Rogers is also changing its cellphone unlocking policy this March so that customers can unlock their wireless phones as early as 90 days after activating their devices on the Rogers network.