If you’ve acquired your iPhone through a contractual agreement with a mobile carrier, there’s a likelihood that the device is locked to that specific service provider. In order to switch to a ...

What is a SIM card used for? A SIM card, or a subscriber identity module/subscriber identification module, is a tiny memory card that contains unique information and is linked to a particular network ...

Activate your iPhone back to AT&T if the SIM card you insert after you install blackra1n onto the device doesn't work properly. Blackra1n is a third-party program that "jailbreaks" SIM-bearing iPhones ...

A SIM card, or subscriber identity module card, is essential component of any phone. It connects your device to a cellular network and stores vital information, including your phone number. Many ...

Sareena was a senior editor for CNET covering the mobile beat, including device reviews. She is a seasoned multimedia journalist with more than a decade's worth of experience producing stories for ...

Major cellular carriers — Verizon, AT&T, T-Mobile, Sprint, and others — typically lock their networks to the iPhone you buy from their stores or pay for via an installment plan. What does that really ...