Once you’ve activated your iPhone with your carrier, it should continue to work on the cellular network without any problems as long as you’re within range of a tower. Nevertheless, the vagaries of ...

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 ...

The subscriber identity module -- SIM -- contains the information used to connect to your wireless carrier's network from your iPhone 4. If you are planning to resell your company's iPhones, you ...

All iPhones and iPads with cellular have a slot on their sides that houses the Subscriber Identity Module (SIM) card provided by your mobile carrier. The SIM card enables your device to access the ...

If your new phone no longer supports SIM cards, or you don't want to use them anymore, you can convert to eSIM instead.