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 ...

We previously reported that a tiny handful of iPhones shipped without SIM cards, while significantly more units have generated the error message "No SIM card ...

If you've just got your hands on a shiny new Sim card, congratulations. Switching your Sim (the chip that dictates your allowance) can unlock huge savings. Now comes the crucial step of activating it ...

AT&T has confirmed in a statement that the new universal Apple SIM card in iPad Air 2 and iPad mini 3 becomes locked to the carrier after being activated on its network. It appears AT&T might be the ...

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 ...