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 ...

SIM cards are important to connect your phone to its network. Here's how to remove and insert SIM cards on your smartphone.

So you've chosen Ultra Mobile as your carrier. Before you start enjoying your plan, you need to install your SIM card – here's a step-by-step guide.