Some owners of Apple's new iPhone 4S have been hit with SIM card error messages, even if they are connected to a CDMA carrier that does not use SIM cards. One reader ...

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 ...

iPhone 4S users are reporting SIM card issues with their handsets. A thread about the topic on the Apple support site has now accumulated more than 200 posts and 30,000 views, suggesting that the ...

If you’ve bought an iPad with 4G/cellular capabilities (we discuss whether that’s a good idea in our 2015 iPad buying guide) or a new iPhone, you need to buy and install a SIM card. Here, we explain ...

A SIM card, or subscriber identity module, is a small card in your cellphone that connects you to the network. Your SIM card contains your phone number, and lets you make phone calls, send text ...