Phone suddenly showing "No SIM" or "Invalid SIM"? Don't panic, there are a few quick checks that can get you reconnected fast ...

If you have a iPhone 13 or older, your device still has a physical SIM card. Here's a guide on how to remove it.

Activating a new SIM card on your iPhone is a simple process that just takes a few easy steps. Read more: Best iPhone of 2024 Follow our step-by-step guide to help get your new iPhone up and running.

If you can't make a call or if you see an error message that your phone's SIM card is not working, there are several ways to troubleshoot the problem.