Turn off Airplane Mode
Make sure Cellular Data is enabled
Restart the iPhone
Remove and reinsert the SIM card
Check for carrier outage
Update carrier settings
Update iOS
Reset Network Settings
Contact your carrier
Contact Apple Support
Turn off Airplane Mode
Make sure Cellular Data is enabled
Restart the iPhone
Remove and reinsert the SIM card
Check for carrier outage
Update carrier settings
Update iOS
Reset Network Settings
Contact your carrier
Contact Apple Support