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 ...

Apple recently seeded a second revision of its iOS 5.0.1 firmware, and besides decrypting key files that aid in the legality of a Siri port, the update seemed to bring nothing new to the table. Some ...

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 ...

While Sprint’s initial batch of iPhone 4S handsets were sold unlocked, allowing you to swap out your Sprint SIM card for a SIM card of your choice, that will no longer be the case. From today, ...

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 ...