Two different faults with two different answers — "No Service" means the phone found no network at all, while full bars and no internet means it found one but is not carrying your data
No Service
- The travel line is switched off
- You are not in a covered country
- The phone has not finished scanning
- Signal is genuinely absent where you are
Signal, No Internet
- Data roaming is off for the travel line
- Mobile data is set to the wrong line
- The plan has run out of data or days
- Wi-Fi is on and the phone is using it
For No Service
- Confirm the travel line is switched on in your mobile data settings
- Flight mode on for ten seconds, then off
- Restart the phone
- In mobile network settings, turn off automatic network selection and pick a network from the list by hand — then set it back to automatic afterwards
- Move somewhere with a clearer view of the sky, and out of the busiest part of the terminal
For Signal but No Internet
- Turn data roaming on for the travel line — this is the single most common cause
- Set mobile data to the travel line
- Turn Wi-Fi off, so the phone actually uses the mobile connection
- Check the remaining data and days on the plan
- Restart the phone
Do not change APN settings at this stage. They are set automatically and are almost never the cause — see What are APN Settings, and do I Need to Change Them?
If both lists are exhausted, start a chat over any Wi-Fi with your order number and ICCID to hand
