When you travel abroad and keep using your phone "as you always do," data roaming can quietly kick in and lead to unexpectedly large bills. The short version: if you switch data roaming OFF before you leave, you can prevent most of these surprise charges. Then, when you actually want to get online abroad, the usual options are an eSIM, a local SIM, a rental Wi-Fi device, or your current carrier's international roaming add-on. This guide first walks you through the settings that keep you safe, then explains how to stay comfortably connected once those settings are in place. Whether it's your first trip or your first in a while, you can prepare calmly before you go. (Information as of June 2026. Prices, supported countries, and conditions can change, so please check the latest details on official or comparison pages.)
- Why surprise bills mostly come from automatic roaming
- How to turn data roaming OFF before departure (iPhone/Android)
- How the four ways to get online after that compare
- Why an eSIM suits first-timers, and how to use one
- How calls and SMS work with a data-only plan
Why using your phone abroad as-is can lead to a big bill
The moment you land in another country, your phone tries to connect automatically to a local network (roaming). The charges this generates are often billed separately from the data allowance in your regular monthly plan, and if you're not covered by a flat-rate roaming option, you usually end up paying as you go. It helps to picture it this way: a pricing structure you never think about at home suddenly comes to the surface when you're abroad.
The scary part is that data can be used even when you're not actively doing anything. App auto-updates, photo cloud sync, automatic email fetching, location services for map apps, and background activity from the operating system all consume data without you noticing. Even if you only meant to "quickly look something up," usage quietly adds up just from the phone sitting there—and that's what leads to an alarming bill later.
Looked at the other way, the cause is simply that the phone roams automatically, so once you stop that traffic, most of the worry disappears. No technical knowledge required. Let's start with the settings to do before you leave.
Many people assume "airplane mode is enough," but roaming can come back the instant you turn airplane mode off. The reliable approach is to turn off data roaming itself, rather than relying on airplane mode.
How to turn data roaming OFF before you go
It's best to set this up calmly at home before your flight. Rushing through it at the airport or on the plane makes it easy to forget a step or tap the wrong thing. Follow the steps for your device. Exact wording and menu paths may differ slightly depending on your device and OS version.
On iPhone
- Open "Settings" → "Cellular" (or "Mobile Data")
- Go to "Cellular Data Options" → set "Data Roaming" to off
- If you'd like extra peace of mind, you can also turn off "Cellular Data" entirely
On Android
- Open "Settings" → "Network & internet" → "Mobile network" (names vary by device)
- Set "Roaming" or "Data roaming" to off
- Consider turning off "Mobile data" as well
Checking once you arrive
After you land, look at the carrier name and signal icon at the top of your screen. Confirming that you haven't accidentally connected to a local carrier network gives you peace of mind. If you're using a travel eSIM, also check that the eSIM you want is the line actually being used, as covered below. For the finer details, see our setup guide.
Turning it OFF also means "no internet"—so plan for what's next
Switching data roaming off prevents big bills, but it also turns off your mobile internet at the same time. Maps, translation, ride-hailing apps, hotel booking confirmations, staying in touch with family—there are so many moments abroad when your phone is exactly what you rely on. "I saved money but can't do anything" would make an otherwise great trip or stay frustrating.
So the recommended approach is to keep roaming off while preparing a separate, safe way to get online. Let's compare the main options in the table below. If you already know where you're going, taking a quick look at your destination on our eSIM comparison page first will make the rest of this easier to picture.
Comparing ways to get online abroad without the big bills
| Option | What it's like | Who it suits |
|---|---|---|
| eSIM | You can sign up and set it up before departure—no swapping a physical SIM. Choose by destination, data amount, and number of days | First-timers / anyone who wants easy prep |
| Local SIM (physical) | Bought locally. You'll need to swap SIMs and get comfortable with the language and process | Long stays, if you don't mind on-the-ground steps |
| Rental Wi-Fi | You carry a device. Easy to share among several people, but you need to charge, return, and pick it up | Family or group trips |
| Carrier roaming add-on | Keep using your usual phone number. Prices and supported countries vary by carrier | Anyone who prioritizes keeping their number and convenience |
There's no single right answer—the best choice depends on length of stay, number of people, budget, and whether you need a phone number. Roaming add-on prices and supported countries differ by carrier and can change, so always check the latest official information before you use one. For a short trip or study-abroad prep where you'd rather not add hassle, an eSIM is easy to choose because you can finish everything before you leave.
How much data do you need? A rough guide
"I don't know how many gigabytes to choose" is a common worry. The table below is only a general guide; actual usage varies a lot with how you use your phone, video quality, and how long you stay. If you're unsure, a safe mindset is to pick a little extra and top up if you run short.
| Main usage | Rough amount per day |
|---|---|
| Mostly maps, search, and messaging (light) | About 0.3–0.5GB |
| Social media, photo sharing, and looking things up too | Around 1GB |
| Video, video calls, and tethering as well | About 2GB or more |
Specific data amounts, durations, and prices vary by plan and country and can change. Please confirm what's actually available in the latest listings on our comparison page.
Why an eSIM suits first-timers, and how to use it with Bloomy
An eSIM writes your data plan directly into your phone, so there's no physical SIM to swap. You can take your time setting it up at home before you leave, and in most cases you simply activate the line once you arrive. Because it works separately from your home line (which you keep with data roaming off), you can stay connected while keeping surprise-bill worries in check. There's also no tiny SIM card to look for or lose—reassuring if it's your first time.
Here's the general flow with Bloomy. Setup is designed so you can move forward with a single tap on the activation link you receive.
- On the comparison page, choose a plan by destination, data amount, and number of days
- After purchase, tap once on the link you receive and follow the on-screen steps to add the eSIM (often done before departure)
- Activate the line after you arrive and start using data
- Check your remaining balance and purchased eSIMs anytime in My Account
Activation timing can vary by plan, so check the guidance before you buy. If you're unsure whether your device supports eSIM, it's worth checking eSIM-compatible devices first. And on devices or in setups where adding by link doesn't go smoothly, adding via QR code or manual setup may also be supported.
What to know if you need a phone number, SMS, or voice calls
Bloomy plans are data-only by design. This is easy to misunderstand, so we'll be straightforward about it. Calls that run over data—that is, app-based calls such as WhatsApp, Messenger, and FaceTime—work as usual. What you can't do is make or receive voice calls on a traditional phone number, or send and receive SMS. Everything that runs on data—maps, translation, social media, the browser, and so on—works fine.
On the other hand, for things like SMS verification codes from banks and other services, or incoming calls to a phone number, a data-only eSIM alone may not cover you. If you need to keep a number, consider keeping your existing line active, or looking at a local plan that includes a number, alongside your eSIM. Where important steps like keeping a number or SMS verification are involved, conditions can change, so please confirm the latest details from official sources.
Who it suits, and who may need an extra step
Let's be honest up front about whether this is a good fit for you.
A data-only eSIM suits you if
- You want easy, before-departure connectivity for a short trip or study-abroad prep
- You mainly use maps, messaging, and looking things up, and app-based calls are enough
- You'd rather avoid swapping or losing a SIM
You may need an extra step if
- You must make voice calls or receive SMS on your regular phone number (pair it with another option)
- You're on a long stay and need a local number (consider a local SIM or a plan with a number)
- You want to share one connection across the family (compare rental Wi-Fi too)
If you can't connect abroad or get stuck on setup
If you've set everything up but still can't connect, don't panic—check the following. Most issues come down to which line is selected or the timing of activation.
- Whether the eSIM (plan) you want is selected as the active line
- Whether data roaming is set as required on that eSIM's side (follow the plan's guidance)
- Try toggling airplane mode on and off once
- Try restarting your device
If that still doesn't fix it, see our troubleshooting guide for situation-by-situation steps, and reach out via Contact if you need help. To brush up on the basics of overseas setup, our eSIM guide is also a good reference.
In short: turn it "OFF" first, then decide how you'll connect
You can largely prevent surprise bills abroad by turning data roaming off before you leave. On top of that, lining up one way to connect—such as an eSIM—so you can still use your phone for maps and messages removes the "I saved money but can't do anything" worry. No complicated steps required: one small bit of prep before departure makes a big difference in peace of mind. If you know where you're headed, browse plans by destination, data amount, and number of days on our comparison page. (Information as of June 2026. Prices, supported countries, and conditions can change, so please check the latest listings.) Communication quality varies with the local network, your device, and the area, and a fair use policy applies.
