1. Ensure you are in an area with mobile coverage.
2. Pull down from the top right of the screen to access the Control Centre.
3. Touch the Airplane icon to activate airplane mode.
4. Wait 10 seconds, then touch the Airplane icon again to deactivate airplane mode.
5. Your iPhone will now search for mobile signal.
6. You may need to reset the network settings, Touch Settings.
Wi-Fi network and passwords, mobile data settings, VPN and APN settings that you have used will be reset when you reset network settings.
7. Touch General.
8. Scroll to and touch Transfer or Reset iPhone.
9. Touch Reset.
10. Touch Reset Network Settings.
11. Enter your passcode.
12. Touch Reset Network Settings.
13. Your iPhone will now restart.