If your iPhone has no service, either because you see an error message or because you can’t make or receive phone calls, there are several possible issues. You may be experiencing service issues, such as a problem with your mobile carrier’s service plan, a hardware problem with your phone, or a misconfigured setting.

If you see the message “No Service” or “SOS” at the top of your iPhone’s screen, chances are that:

Oh, we assume your bill has been paid and your provider hasn't turned off your connection (that happened to us).

Before we change any iPhone settings or do more time-consuming troubleshooting tasks, let’s tackle the easiest and most likely solutions first. If those don’t fix the problem, we’ll move on to more advanced potential solutions.