Update Your iPhone

Another thing you might need to update is your iPhone itself. There may be a bug or software issue that’s preventing you from making phone calls.

Keeping your iPhone up to date might not just fix this issue, but it might also bring a couple of new features you didn’t even know were coming. Here’s how to update your iPhone:

1. Open the Settings app.
2. Scroll down and go to General.
3. Tap on Software Update.
4. If there is an update available, tap on Install Now.

If nothing new appears here, then you’re already running the latest version of iOS that’s available for your iPhone.