Why Is My Data Not Working? A Symptom-by-Symptom Fix for eSIM Travelers
Quick fix: On a travel eSIM, data usually fails for one of three reasons:
- data roaming is off on the eSIM line;
- mobile data is set to the wrong line;
- the plan isn’t active in the country you’re in.
Check those three settings, then toggle Airplane mode off and on. If you have signal bars but still no internet, check the APN (step 5).
First, find your symptom
| What you see | Most likely cause | Go to |
|---|---|---|
| No bars, "No Service" or "SOS" on the eSIM line | Line off, not yet in the destination country, or the phone is on a network your plan can’t use | Steps 1, 2, 6 |
| Bars and 4G/5G shown, but no internet | Data roaming off, wrong data line, APN | Steps 2, 3, 5 |
| An error like "PDP authentication failure" | The network refused the data session | PDP authentication failure guide |
| Internet works but very slowly | Daily high-speed allowance used up, or congested network | Step 7 |
| Internet works except in one app | Mobile data is turned off for that app | Step 8 |
Step 1: Check where you are and which plan you have
A country plan connects only in that country. If you’ve crossed a border, the eSIM won’t connect until you’re back, unless you have a regional or global plan that covers both countries.
The validity of a TravelNet plan starts when it first connects at your destination. If you installed it before you left, it’s normal that it has no data at home.
Step 2: Turn on the line and data roaming
iPhone: Settings > Cellular (or Mobile Data) > tap the eSIM > turn on Turn On This Line and Data Roaming.
Android: Settings > Network & internet > SIMs (Samsung: Connections > SIM manager) > make sure the eSIM is on. Then turn on Roaming (Samsung: Connections > Mobile networks > Data roaming).
A travel eSIM always connects through a partner network, so it needs roaming turned on even though you aren’t charged roaming fees. If you don’t want roaming charges from your home carrier, leave data roaming off on your home SIM. Keep it on only for the eSIM.
Step 3: Send mobile data through the eSIM
- iPhone: Settings > Cellular > Cellular Data > choose the eSIM. Turn off Allow Cellular Data Switching so data doesn’t move to your home line without you noticing.
- Android: Settings > Network & internet > SIMs > Mobile data > choose the eSIM. Samsung: Connections > SIM manager > Mobile data.
Step 4: Toggle Airplane mode, then restart
Airplane mode on, wait 10 seconds, then off. This makes the phone search for the network again. If that doesn’t help, restart the phone. It fixes more cases than you’d expect, especially after a long flight.
Step 5: Check the APN
If you have bars but no internet after steps 2 and 3, check the APN:
- iPhone: Settings > Cellular > eSIM line > Cellular Data Network (only visible if the provider allows editing). Remove any values you entered yourself.
- Android: eSIM settings > Access Point Names > select the APN that came with the plan, or menu > Reset to default.
The APN is normally set automatically. Only enter one by hand if your provider tells you to, and copy it exactly.
Step 6: Pick a network manually
iPhone: Settings > Cellular > eSIM line > Network Selection > turn off Automatic and choose a network.
Android: eSIM settings > Network operators > turn off Select automatically.
Try each network listed, one at a time, then go back to Automatic once data works. This helps in border areas and right after landing, when the phone sometimes stays on a network the plan doesn’t use.
Step 7: Very slow data? Check your allowance and the network
- Fixed-data plans: check how much data is left. When the allowance runs out, data stops. To size your next plan, use the data calculator.
- Unlimited plans: many travel eSIM plans keep full speed only up to a daily high-speed allowance. TravelNet’s Unlimited Standard and Unlimited Plus plans work this way: once the daily allowance is used, speed is reduced for the rest of the day. The allowance and the reduced speed depend on the plan and the destination. Each destination page shows the exact figures, for example France, Japan or the USA.
- Congestion: at stadiums, festivals or airports, speed can drop for everyone on the network. Moving a few hundred metres often helps.
- Low Data Mode (iPhone, Settings > Cellular > eSIM > Data Mode) or Data saver (Android) limits background data. Turn it off if apps seem stuck.
Step 8: Internet works, except in one app
iPhone: Settings > Cellular > scroll to the app list and make sure the app’s switch is on.
Android: Settings > Apps > the app > Mobile data > allow mobile data and, if it’s there, background data.
A VPN can also block some apps. Turn it off to test.
When to contact support
Contact your eSIM provider if you’ve done all of the following and data still doesn’t work:
- you’re in a covered country;
- the line and data roaming are on;
- the eSIM is selected for mobile data;
- you’ve restarted the phone and tried another network.
Send them your order number, the country you’re in and a screenshot of the eSIM settings.
TravelNet customers: contact support or email support@travelnet-esim.com. If a technical issue stops the eSIM from working, the refund policy applies within 14 days of purchase.
FAQ
Why do I have signal bars but no internet on my eSIM?
The phone is registered on a network but can’t open a data session. Most often data roaming is off on the eSIM line, mobile data is set to your home SIM, or the APN is wrong.
Do I need data roaming on for a travel eSIM?
Yes, on the eSIM line. Travel eSIMs connect through partner networks, which the phone treats as roaming. Turning it on for the eSIM doesn’t affect your home SIM, where you can leave roaming off.
My eSIM worked yesterday and stopped today. Why?
Check whether the plan expired or ran out of data, or whether you crossed into a country your plan doesn’t cover. On unlimited plans, a sudden slowdown usually means the daily high-speed allowance has been used.
Will a factory reset fix my eSIM data?
Don’t do it. A reset can delete the eSIM, and many travel eSIMs can’t be reinstalled from the same QR code. The steps above solve almost all data problems without it.
Can I use my eSIM data as a hotspot?
That depends on the provider and plan. TravelNet destination pages state whether hotspot is included. If hotspot data doesn’t work while the phone’s own data does, check the APN (step 5).
Related guides
TravelNet
Guides written by TravelNet eSIM, based on our plan data and partner networks.