The short answer: you don't need to remove the SIM
You don't need to take the chip out. Just turn off data roaming on your regular line and turn it on for the eSIM line. Being registered on a foreign network doesn't trigger a charge by itself — what gets billed is actual usage. If you want zero risk, disable the entire line from your settings.
That's the question that comes up before every trip, and it almost always carries the same underlying worry: you turn off roaming, get on the plane, and still see a charge or your balance disappears for no reason. That's why the short answer isn't enough. What really puts your mind at ease is knowing what to turn off, what to leave on, and why there's one setting you actually need to turn on, not off.
How roaming actually gets charged
Roaming isn't a toll for being connected. When you land, your phone looks for a network in the destination country and registers on it. That registration alone doesn't generate a bill. What gets billed is usage: data your phone downloads, calls you make, calls you receive on some plans, and messages you send.
That's the nuance almost nobody explains well. Many carriers sell travel packages that aren't activated manually — they kick in automatically with the first bit of usage outside your home country, and from that moment on they apply a fee, usually daily. It doesn't matter if that first usage was an app update in the background while your phone was in your pocket at the immigration line. The package is already triggered and your balance starts dropping.
This explains the pattern that scares people the most: you swear you didn't use your phone and still ran out of credit. There wasn't a charge for breathing. There was a tiny bit of usage that opened the door to a rate.
The practical takeaway changes the goal. It's not about being disconnected or keeping your phone off. It's about making sure your home line consumes absolutely nothing while you're away. Zero bytes, zero outgoing calls. If you achieve that, the SIM can stay safely inside your phone.
It's also worth checking the exact terms of your plan before you leave, because zones vary a lot. The same carrier might include usage in neighboring countries and charge separately for destinations on another continent. If you're unsure which option works better for your trip, the comparison between using a data eSIM or paying your carrier's roaming is the place to start.
Turn off on one line, turn on on the other
This is where almost everyone gets stuck, and it's worth saying twice because it's counterintuitive.
A travel eSIM is a line from a foreign carrier. For it to work in the country you're visiting, that carrier uses agreements with local networks. Technically, your phone is roaming on that line. If you leave data roaming turned off on the eSIM, you won't get online. You'll see the signal, you'll see a network name, and nothing will load.
So the two settings go in opposite directions, each on its own line:
The goal isn't to turn off your phone — it's to make sure your home line doesn't use a single byte while the eSIM does all the work. That's why data roaming gets turned off on one line and turned on on the other. Anyone who turns both off ends up with no internet and thinks the eSIM is defective.
When someone says they bought the eSIM and it didn't work when they arrived, the cause is usually right here, or because they left their home line as the default data line. It's not that the chip is bad. It's that the phone has two lines and you need to tell it which one to use for what.
| Setting | Your regular line | Your travel eSIM |
|---|---|---|
| Data roaming | Off | On |
| Default data line | No | Yes |
| Automatic data line switching | Disabled, so your phone doesn't jump to the wrong line on its own | |
| Calls and SMS | Your number, if you want to keep receiving codes | Data only on most travel plans |
| Background data and app updates | Limited while you're away, especially before you finish setting up | |
Which option works for you based on your situation
There are four reasonable ways to handle your home SIM while traveling. None is right for everyone. It depends on whether you need to keep receiving messages on your number and how much peace of mind you want.
| What you do | Do you browse with the eSIM? | Do you receive SMS and calls on your number? | Risk of charges | Who it's for |
|---|---|---|---|---|
| Leave the SIM in with data roaming off | Yes | Yes | Low, except for calls and messages you initiate yourself | Most travelers |
| Leave the SIM in but disable the line in settings | Yes | No | Virtually none | Anyone who doesn't want to think about it |
| Remove the physical SIM | Yes | No | None | Anyone who truly can't rest easy otherwise |
| Airplane mode with Wi-Fi on | No | No | None | Only if you'll rely on hotel Wi-Fi |
Two warnings about the last two rows. Removing the SIM seems like the safest option, but it swaps one fear for another: the tray and the chip are tiny, they get lost on a hostel table with ridiculous ease, and when you get home you're left without communication just when you need your number. Also, if your home line is already an eSIM, there's nothing to remove and the only way is to disable it from settings.
Airplane mode, on the other hand, turns off all lines at once, including the travel eSIM. You can turn Wi-Fi back on, but you won't have cellular data. It's fine for the flight, not for the trip.
iPhone: exactly what to tap
The names change slightly depending on the version and country. Some show Cellular Data and others Mobile Data, but the path is the same.
On your regular line
- Open Settings and go to Cellular Data.
- Tap the name of your primary line in the list above.
- Turn off Data Roaming.
- If you want total blocking, also turn off the Turn On This Line switch. The line goes dormant and the number stops receiving anything until you reactivate it.
On the eSIM line
- Go back to Cellular Data and tap the eSIM line.
- Turn on Data Roaming. Without this you won't browse.
- Go back to the previous screen and, in the Cellular Data section of that same screen, choose the eSIM as the data line.
- On that same screen, turn off Allow Cellular Data Switching. That switch is what makes the iPhone automatically switch to the other line when it thinks there's a better signal.
One detail that saves you scares: also check Wi-Fi Assist. That feature jumps to cellular data when Wi-Fi is slow, and it uses the line you have set for data, i.e., the eSIM. With data roaming off on your home line, it can't generate a charge with your carrier, but it eats up your travel plan without you noticing, so it's best to turn it off too. If it's your first time installing one of these lines, the complete step-by-step installation guide for iPhone and Android covers scanning the code and the naming of each menu.
Android: exactly what to tap
Here the variety is greater, because each manufacturer renames the menus. On Samsung devices it's usually in Settings then Connections. On Google Pixel and stock Android, in Network & Internet. On Xiaomi and other skins, in SIM cards & mobile networks.
On your regular line
- Go to the SIMs or mobile networks section and select your primary line.
- Turn off Data Roaming or Data Roaming.
- If you prefer absolute silence, use the switch that disables that SIM. On Samsung it's inside the SIM card manager.
On the eSIM line
- Select the eSIM in the same list of lines.
- Turn on Data Roaming on that line.
- Set it as Preferred SIM for mobile data.
- Find the option for automatic data switching between SIMs and leave it turned off.
If after finishing it still doesn't load anything, there are two things that solve most cases: restart your phone once at the destination and, if the problem persists, manually select a network from the country in the network search instead of leaving it on automatic. Travel plans rely on several local networks, and sometimes the phone clings to one with poor coverage at that specific spot.
Where phantom usage comes from
When someone says they didn't touch anything and still got charged, there's almost always one of these causes behind it. It's worth reviewing them before you leave, because they all get resolved in a couple of minutes.
| How it leaks | What happens | How to stop it |
|---|---|---|
| Background apps | They sync email, photos, or updates as soon as there's a network, even if you don't touch the screen | Data roaming off on that line and limited background refresh |
| Incoming calls | On many plans, answering outside the country costs, and sometimes even ringing and going to voicemail | Divert voicemail, notify family, or put the line to sleep |
| Wi-Fi calling | It's billed according to your carrier's terms even if you're on hotel Wi-Fi | Check your plan before leaving and use calling apps if in doubt |
| Automatic line switching | The phone decides to switch to the home line when the other loses signal for a moment | Turn off automatic data switching |
| Multimedia messages | MMS and some group messages travel over data, not SMS | Disable MMS sending while you're away |
| Auto-activated travel package | A minimal usage triggers the carrier's daily rate for the entire day | Zero usage on that line, not low usage |
Notice the last row, because it's the one that explains the most frustrating stories. The difference between spending little and spending nothing is not a matter of degree. With many travel plans, it's the difference between paying a full fee and paying nothing.
Stop turning off data every time you put your phone away
There's a kind of anxiety that's a close cousin to the first one, and it ruins entire trips: the habit of turning data on and off every time you put your phone in your pocket, just in case. It gives a false sense of control and does nothing useful.
If you have data roaming turned off on your home line, that line won't use data even if the main data switch is on. And if you're browsing with a travel eSIM, that plan is already paid for — using its data is exactly what you bought. Turning it off every so often only means messages don't come through, the map doesn't load when you need it, and you spend the trip glued to your phone instead of the place you're in.
What you actually want to do is the opposite: set everything up properly once, before you leave, and then never touch it again. After that, if you want to keep an eye on how much you've used, check the per-line data counter that both iPhone and Android have. That's useful info. Turning things on and off isn't.
And if the plan you bought is advertised as unlimited data, read the fair-use fine print before you get too comfortable: it's common that after a certain volume the speed drops noticeably, so the real unlimited is usually unlimited at reduced speed.
Calls, WhatsApp, and bank SMS
This is where the decision gets personal, because not everyone has the same ties to their number.
Bank codes
Many banks still send purchase confirmations and login codes by SMS to the registered number. Receiving an SMS is usually not charged, but that depends on the plan and you need to confirm it. If you rely on those codes, the sensible option is the first row of the table: SIM in, data roaming off, line active only for receiving. If instead you deactivate the line or remove the chip, those messages won't arrive and you could end up unable to pay at your destination.
Calling family
This is a very common need for people with elderly parents or grandparents: talking every day, and talking on a regular phone call, not through an app the other person doesn't know how to use. With a data-only plan you don't get a new phone number to call from, so there are two honest options. One is to use your home line only for those calls, accepting whatever voice roaming cost your carrier charges. The other is to have a calling app installed and tested on the other person's phone before you leave, with the video call set up and the icon visible.
WhatsApp and your number
WhatsApp stays associated with the number it was registered with and keeps working over data, no matter where the data comes from. You can remove the SIM, browse with the eSIM, and keep your conversations intact. The only real caution is not to delete or reinstall the app during the trip, because then you will need to receive a verification code on that number. If you've never had one of these lines, it's worth understanding what exactly an eSIM is and how it differs from the traditional card before changing anything.
Before you leave and once at your destination
What to do at home, on Wi-Fi
You install an eSIM with an internet connection, so the right time is before you leave, sitting down calmly, not at the arrival airport hunting for a Wi-Fi that asks for a local number. Activation takes about a minute, and buying it in advance doesn't commit you to anything: you have 180 days to activate it from purchase, so you can set it up weeks before your flight.
Before buying, check just one thing: that your phone supports eSIM and is carrier-unlocked. This is the part many people discover too late, and not all popular models have it. The updated list of eSIM-compatible phones clears it up in a moment, and if you prefer to understand the key differences, the comparison between an eSIM and a physical SIM card explains what you gain and lose with each.
What to do when you land
- Turn off airplane mode.
- Check that the active data line is the eSIM and that its data roaming is on.
- Check that your home line has data roaming turned off.
- Wait for your phone to register on a local network. If it takes a while, restart it.
If something isn't working, don't keep trying blindly in the taxi line. PuraSIM support is available 24/7 in all languages via email and WhatsApp, and the first thing worth checking is which of the two lines is selected for data. To choose the plan for the country you're going to, the collection of popular destinations brings together the most requested ones, within coverage spanning over 200 destinations.
Frequently asked questions
When should I turn off data roaming?
Before you leave your country, not when you arrive. As soon as your phone detects a foreign network, it might sync something in the background, and with certain plans that minimal usage is enough to trigger the daily travel rate. Keep the setting off on your regular line from the moment you leave home, and keep it that way until you return. If you also turn off the entire line, you don't have to think about it anymore.
Do I need to turn data roaming on or off?
Both, but on different lines. On your regular line it should be off, because that's the one that can generate charges with your carrier. On your travel eSIM line it should be on, because that line works precisely by connecting to networks in another country. This is the most common mistake: people turn off roaming on the entire phone, lose their internet, and think the eSIM was defective.
What do I do with my SIM card when I travel abroad?
You have four options, sorted from least to most drastic. Leave it in with data roaming off, which works for most people. Leave it in but with the line deactivated in settings, if you don't want to think about it. Remove the physical SIM, if that's the only way to be sure. Or turn on Airplane Mode, which also turns off the eSIM and only makes sense if you're going to use Wi-Fi. The difference between them is whether you still receive calls and messages on your number.
Do you need to turn off data roaming with an eSIM?
No. On the eSIM, it needs to be on. A travel plan is a foreign line that uses the networks of the country you're visiting, so your phone sees it as roaming. If you leave that switch off, you'll see signal and network name, but nothing will load. Turn it on only on that line and leave your home carrier's line off.
Can I be charged even if I have data turned off?
For data, no, if roaming is off on that line. Through other means, yes. Calls you make or receive count according to your plan, multimedia messages travel over data even if they look like SMS, and in some cases even calls diverted to voicemail generate a charge. If you want to close all doors at once, deactivate the entire line from settings instead of just turning off data.
How do I know which of the two lines is using the data?
On your phone's status bar, you'll see the indicator for the line that's using data. In the cellular data settings, you'll see which line is marked as default, and also a data usage counter separated by line. Check it on the first day at your destination. If your home line's counter moves, something was misconfigured, almost always the automatic data switching between lines.
If I remove the SIM, do I lose WhatsApp?
No. WhatsApp stays linked to the number it was registered with and works with any internet connection, including a travel eSIM. Your chats, groups, and contacts remain the same. The only risk is deleting or reinstalling the app during your trip, because then you'd need to receive a verification code on that number. Leave the app installed and have a backup done before you leave.
My phone doesn't seem to support eSIM and I can't find the EID number, what do I do?
If the EID doesn't appear in the device info, it's likely that model doesn't support eSIM or the regional version you bought doesn't have it. It could also be locked by the carrier that sold it, which is common with financed devices. Check the exact model in the compatible list before buying any plan. If it's not compatible, the alternative is still a local physical SIM or your carrier's travel package.
The decision
Leave the SIM inside your phone. Turn off data roaming on that line, turn it on on the eSIM line, set the eSIM as the data line, and disable automatic switching between lines. With that sorted, your number will still receive bank codes and you won't incur charges with your carrier.
Make an exception in two specific cases. If you don't need to receive anything on your number during the trip, disable the entire line from the settings: it's just as safe as removing the chip and you won't risk losing it. And if your plan charges for receiving calls and you have people who call you daily, that same deactivation avoids the drain, provided you've agreed beforehand on which channel they'll use to talk.
Physically remove the SIM only if none of the above helps you sleep at night. It's an emotional decision, not a technical one, and it has a real cost: a tiny object you can lose far from home, just when you need it to get back to normal.
