Do I need to turn on data roaming?
Yes — but only for the eSIM line. Travel plans work by roaming onto partner networks. Keep data roaming switched off on your home SIM so your home operator cannot bill you.
Whether you need to switch on data roaming sounds like a simple question, but a correct answer needs to be clear about which line is being discussed, since a phone in the eSIM era almost always carries two lines at once: the home SIM tied to your home country provider, and the eSIM bought for this trip. The switch-on rule for these two lines is the exact opposite of each other. This page explains why, where to check it on the phone, and what to do if a connection still fails after roaming has already been switched on.
It is written for anyone preparing a phone before their first trip with an eSIM, anyone who has just landed and cannot get connected, and anyone worried about being billed by their home country provider without meaning to. Everything here covers the general principle of how roaming works, not the specific rule of any one particular carrier.
Why roaming needs to be on for the eSIM line specifically
Most travel plans do not operate their own towers in every country; instead, your phone connects to a partner network at the destination, which is exactly the mechanism called roaming. If data roaming is switched off for the eSIM line, the phone can see the partner network but will refuse to connect data through it, so the internet does not work even with a full signal shown.
Switching on data roaming for the eSIM line is therefore not an optional extra but a necessary condition for the plan to work at all, unlike using a SIM in your home country, which never relies on roaming since it connects directly to its own network.
Why data roaming should stay off on the home SIM
While the eSIM line needs roaming switched on to work, your home SIM is the exact opposite. Leaving data roaming on for the home SIM while abroad can let the phone connect data through that line automatically, which typically carries a roaming charge from your home country provider that runs far higher than usual, and is an entirely separate matter from the eSIM plan you bought.
Turning off data roaming on the home SIM does not affect making or receiving calls on that SIM, since calls and SMS run on a mechanism entirely separate from data. The only thing switched off is that SIM's internet connection.
The dual-SIM setup you actually want
With both the home SIM and the travel eSIM installed at once, the correct setup is to switch data roaming on for the eSIM line only, and keep it off for the home SIM at all times. The line set as the default for data should be the eSIM, so the phone pulls its internet from that line automatically instead of switching back and forth.
The default line for calls and SMS usually stays the home SIM, since that is the number people already know to reach you on. The menu for choosing which line is the default for which purpose sits in the same screen as the roaming setting, but its exact position varies by handset manufacturer and operating system version.
The menu you need to open on the phone
The data roaming setting exists per line, not as one single switch controlling the whole phone. You therefore need to set it correctly line by line. The wording differs slightly between iOS and Android, and the position can shift depending on the operating system version or handset manufacturer.
If you are unsure where the menu sits on your specific phone, search for the word 'roaming' in the settings app's search box, which is available on most iOS and Android phones. This is usually faster than navigating menu by menu when you are unfamiliar with that particular model.
The most common mistake
The most common mistake is switching data roaming on for both lines at once, or off for both at once, when the correct setup is on for the eSIM only and off for the home SIM only. This usually comes from assuming roaming is one single switch for the whole phone, when in fact it is set separately per line.
Another common mistake is leaving airplane mode on for the whole trip out of fear of charges, which disables every line's connection, including the eSIM already paid for. The correct approach is to switch off only the home SIM's data roaming, not everything at once through airplane mode.
Connecting to the partner network, not a home network
After switching on roaming for the eSIM line, it is worth checking that the phone is genuinely connecting to a network at the destination, not a home network that happens to be picked up near a border or a particular airport. The network name shown on that line's menu tells you which carrier it is actually connected through.
If the network name shown does not match what was expected, try briefly switching airplane mode on and then off again, so the phone searches for a network afresh. This often resolves the phone being stuck on an unsuitable network in many cases.
Some phones display the network name as a short code instead of the carrier's full name, which is normal on certain models and does not mean the connection is on the wrong network. If it is unclear whether that code refers to the genuine partner network, treat whether the internet actually works as the main signal, rather than reading the name alone.
Travelling through several countries on one trip
If your plan is a regional one covering several countries, the roaming setting does not need to change at all when crossing a border, since the same eSIM line automatically connects to whichever partner network suits each country, as long as roaming for that line stays switched on.
What is worth doing when crossing a border is checking the network name after a short while, to confirm the phone has genuinely switched to a partner network in the new country, rather than remaining stuck on the previous country's network.
Setting this up before you board
- Data roaming switched on for the eSIM line
- Data roaming switched off for the home SIM
- The default line for data set to the eSIM
- Airplane mode switched off, since it is not the correct fix for avoiding charges
- A quick internet test done once, before leaving somewhere with Wi-Fi to fall back on, to confirm the setup is correct
How to check the roaming setup on your phone
- 1iOS: check roaming for each line separatelyOpen Settings → Mobile Service / Cellular, tap into the eSIM line and switch Data Roaming on, then tap back into the home SIM and confirm Data Roaming is off there. The exact wording of this menu can vary slightly by your iOS version.
- 2Android: check on the SIMs screenOpen Settings → Network & internet → SIMs, tap into the eSIM profile and switch data roaming on, then tap into the home SIM and confirm it is off. Menu names and positions vary by handset manufacturer and Android version.
- 3Set the default line for dataThe same screen usually has an option for which line is the default for data. Choose the eSIM so the phone pulls its internet from that line automatically.
- 4Test before leaving Wi-FiOpen a web browser or any app that needs the internet while still somewhere with Wi-Fi to fall back on, to confirm the setup is correct before actually having to rely on roaming data.
Common connection symptoms
The table below summarises common symptoms around roaming data connections, the likely cause, and what to do, so you can quickly tell whether the fix is in the phone's settings or worth contacting the team about.
| Symptom | Likely cause | What to do |
|---|---|---|
| Full signal shown but no internet works | Data roaming for the eSIM line is still off, even though it has connected to the partner network | Switch on data roaming for the eSIM line in the phone's network menu |
| The phone is pulling internet from the home SIM by mistake | The default line for data is still set to the home SIM, not the eSIM | Open the default-line setting and change it to the eSIM |
| No network found to connect to at all | You may be outside the partner network's coverage area in that particular spot | Try briefly switching airplane mode on and off, or move to a slightly different spot and try again |
| Connects at first then drops intermittently | The partner network's signal is weak in that particular spot, or the phone is switching between networks | Check the network name shown; if it keeps switching, try toggling airplane mode so the phone settles on one network |
If it still will not connect after checking everything
If you have checked both lines, toggled airplane mode, and the internet still does not connect, contact the team with a screenshot of the network menu showing the line name and status, along with your order number, so the system-side status can be checked against what the phone is showing.
Do not delete the eSIM profile to try reinstalling it before hearing back from the team, since a profile normally installs only once. Deleting it unnecessarily could mean that plan can no longer be used at all.
FAQ
Can I also switch on roaming for the home SIM as a backup signal?+
Technically yes, but it is not recommended, since it typically carries a roaming charge from your home country provider that runs far higher than usual. Rely on the eSIM line as the main connection instead, and keep the home SIM's roaming switched off.
Why is there still no signal even after switching on the eSIM's roaming?+
It may be that the phone has not yet connected to a partner network at all. Try briefly toggling airplane mode, or move to a spot where signal should be better. If that still does not help, contact the team.
Does leaving airplane mode on for the whole trip save on charges?+
Not in the way intended, since airplane mode disables every line's connection, including the eSIM already paid for. The correct approach is to switch off only the home SIM's data roaming.
Does a regional plan need roaming switched on and off again every time you cross a country?+
No. As long as roaming for the eSIM line stays switched on, the phone connects to whichever partner network suits each country automatically when you cross a border.
If the setup was wrong and a charge came through on the home SIM, what should I do?+
That is a matter for your home SIM's own provider directly, not the eSIM plan bought from us. Contact your home provider about that specific charge, and make sure the home SIM's roaming setting is off before your next trip.
Should roaming be switched on before boarding, or is it fine to wait until arrival?+
It is fine to switch it on before boarding, since turning on roaming for the eSIM line does not connect to anything until the phone actually finds a partner network at the destination. Setting it up in advance saves having to hunt through menus right after landing.