Sareena was a senior editor for CNET covering the mobile beat, including device reviews. She is a seasoned multimedia journalist with more than a decade's worth of experience producing stories for ...

While most people seem to manage just fine with a single SIM card in their smartphone, some -- especially travelers, who can save money by fitting a local SIM card into their handset -- love the ...

Seeing “No SIM” or “Invalid SIM” on iPhone? Check your SIM card, restart, or update your carrier settings. Simple fixes often ...

All modern iPhones and iPads now use nano-SIM cards. Unfortunately, this can be a bit of a problem for anyone switching from an older device, because the nano-SIM is much smaller than the micro-SIMs ...

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 ...

To remove the SIM card from your iPhone, all you need is a SIM card ejection tool or paperclip. Sticking the ejection tool into your iPhone's SIM card tray will remove the card. Your iPhone's SIM card ...