Follow these steps to troubleshoot a phone that won’t connect to mobile data:

1. Verify that you have an active cellular data plan.
2. Check the connection settings with your mobile service provider.
3. Restart your device.
4. Update your carrier settings.
5. Toggle your Airplane Mode on and off.
6. Check for a software update.
7. Update your profile.
8. Check for a system update.
9. Reset your Network settings.