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 ...

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 ...

In a first for US wireless carriers, Sprint and Verizon Wireless will allow iPhone 4S customers to unlock their mirco-SIM card slots, which enables use on wireless networks around the world, reports ...

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 ...

Contrary to initial reports, the Sprint version of the iPhone 4S will not come with an unlocked microSIM slot allowing customers to pop in international SIMs; it will be able to roam on international ...