So you’ve chosen Ultra Mobile as your carrier. Great choice! But before you start enjoying those international calling features or high-speed data, you need to install your SIM card. Don’t worry; ...

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 ...

A SIM card, or subscriber identity module, is a small card in your cellphone that lets you place phone calls, send text messages, and more.

Changing carriers can be exciting. You might get to pick up a new phone, or maybe you want better coverage in your home area. Either way, you have to know how to get set up. Each carrier tackles SIM ...

You can activate a new or used iPhone for use with a cellular service provider in a few steps. Here's how to activate any iPhone, or troubleshoot it.

So you're in a pinch, and you need to swap out the SIM card or install a microSD in your Android device, but you can't find the nifty little ejector tool that came in the device's retail box. Fret not ...