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 ...

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 ...

eSIMs are catching on with carriers, even budget-minded providers like Cricket Wireless. Assuming you’ve got a compatible phone, here’s how to activate a Cricket eSIM, transfer one to a new phone, or ...

After you purchase and use your cellphone for an extended period of time, you can change networks. However, the phone that you're currently using may not be offered on that network. If you wish to ...