An unlocked AT&T wireless phone is a device that can operate on a different wireless carrier network. The company reserves the right not to grant requests for unlock instructions if AT&T deems it necessary.
A carrier lock is a software code that is programmed on a wireless phone or tablet to secure and prevent the device from working on another wireless network. This feature is typically used by carriers that use the Global System for Mobiles (GSM) technology, such as AT&T in the United States.
Users of locked AT&T devices are entitled to have their phones unlocked if they do not have outstanding debts and they fulfill certain eligibility requirements. Once an unlock request is submitted, AT&T usually responds within 2 business days.