A dual-SIM setup lets you use one phone to make and receive calls and texts from two numbers. It's also super convenient and can save you serious cash when traveling. We show you how to use two SIMs ...

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

The newer eSIM technology, which is quickly becoming the standard on high-end phones, is safer and more convenient.

As the iPhone Air goes eSIM-only, and some of the best Android phones also drop the SIM card tray, here's a look at the eSM, ...