Unexpected International Phone Bills? Settings and Safer Ways to Stay Connected Abroad

Last updated: June 2026

When you arrive somewhere new and turn on your phone, using it just like you would at home can result in unexpectedly high charges. Your phone may connect to local networks through international roaming without realizing it. The solution is simple: turn off data roaming before you travel. This alone prevents unintended charges. If you want to use maps and translation apps while traveling, set up an alternative connection like an eSIM or rely on Wi-Fi.

Many people feel unsure about the settings terminology or worry after hearing stories of massive phone bills. This guide explains why international charges happen in the first place, walks you through disabling data roaming on both iPhone and Android, and shows you the safest ways to stay connected. By the end, you'll know exactly what to do.

Why do international phone bills get so high?

The core issue is this: your home mobile plan assumes you'll use it at home. When you travel and use your phone normally, it connects to a local carrier's network—a process called international roaming. This roaming has a completely different pricing structure than your home network. If apps update, maps load, or clouds sync, data charges stack up quickly. This unexpected bill is sometimes called "bill shock." Rates per data unit are often higher internationally than at home. Before you travel, check with your mobile carrier to understand exactly how international roaming is priced on your plan.

Sometimes carriers offer international data plans, but terms, daily limits, and covered countries vary by operator. Check your carrier's latest information before departure.

How data quietly builds up without you noticing

• You open maps or social media right after landing to find directions
• Apps and your operating system download updates in the background
• Photos automatically sync to iCloud, Google Photos, or other cloud storage
• Email and messaging apps receive new messages, including images and videos that download automatically
• Music or video streaming apps use data even when you think they're in offline mode

You might feel like you barely touched your phone, but these background activities add up fast. Photos from your trip syncing over a foreign network can use far more data than you'd expect. That's why stopping the connection before you start is the most reliable defense.

Watch out during layovers and immediately after landing

The moment your plane lands and you turn on your phone—or during a layover in another country—roaming can start. If you plan to configure settings later, automatic background connections might already be running during your layover.

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The most important setting: turn off data roaming

To prevent unexpected charges, turn off data roaming first. This stops your phone from using the local network for data and prevents unwanted billing. Do this before you travel, while still at home. It's safer than adjusting settings after landing, and reduces the risk of accidental mistakes. A day before departure is ideal.

On iPhone

1. Open Settings
2. Tap Mobile Data
3. Open Mobile Data Options
4. Turn off Data Roaming

If you have multiple SIM lines, confirm which one you're turning off. For extra safety, turn off Mobile Data entirely on any lines you won't be using.

On Android

The exact steps vary slightly by manufacturer, but follow this general path:

1. Open Settings
2. Open Network & Internet or Connections
3. Select Mobile Network (or your SIM)
4. Turn off Data Roaming (or Roaming)

If you can't find it, search for "roaming" in Settings to locate it faster. Some phones have a quick settings toggle. If you use dual SIM, check roaming settings on each line separately.

Settings names and locations vary by device. If you're unsure or want to confirm eSIM compatibility, check the compatible devices page and setup guide.

After you arrive

Once you land, check the carrier name and signal bars at the top of your screen to make sure you haven't accidentally connected to a local network.

Managing roaming settings: per-line considerations

Data roaming settings live in Mobile Data (or Mobile Network) settings, and each line has its own switch. Select the correct line before making changes to avoid confusion about which one you're adjusting.

Label your SIM lines

With two or more SIM lines, your phone shows "Primary" or "Secondary" labels that don't describe their purpose. Both iPhone and most Android phones let you rename each SIM. Calling them "Home SIM" and "Travel eSIM" makes it much easier to switch the right one while traveling, especially when you're not thinking clearly after a long journey.

Airplane mode vs. data roaming vs. mobile data off: what's the difference

These three settings look similar but work very differently. Understanding the distinction prevents confusion.

Setting	What stops	What still works	Best for
Data roaming off	International data for that line	Wi-Fi, other lines	Keeping your home line active while avoiding international charges
Mobile data off	All data for that line	Wi-Fi	Not using data at all, at home or abroad
Airplane mode on	All cellular, Wi-Fi, and Bluetooth (initially)	Wi-Fi and Bluetooth if re-enabled separately	Ensuring no connection during takeoff and landing

With airplane mode on, you can't use an eSIM. To use data abroad, turn off airplane mode and activate only the line you want to use. Call and SMS charges during roaming depend on your carrier's terms—check before you travel.

Timeline: before departure to after return

Break your prep into stages so nothing falls through the cracks.

When	What to do	Why
A few days before	Decide on connectivity (roaming plan, eSIM, or Wi-Fi). Confirm eSIM compatibility.	No scrambling at the last minute
The day before	If using eSIM, install it at home over a stable Wi-Fi connection	Setup is easier in a known environment
Travel day (airport)	Turn off app auto-update, background refresh, and photo backup	Prevent large unexpected data use
Before takeoff	Turn off data roaming on any lines you won't use	Stop accidental charges on your home line
After landing	Activate the line you'll use and verify the carrier name at the top of your screen	Confirm you're on the right network
After return	Switch data back to your home line. Turn off or delete the eSIM. Re-enable updates and backup.	Resume normal phone service

Auto-updates and photo backup have the biggest impact. Photos and videos can use hundreds of MB to several GB at a time, which adds up fast on a trip. After you get home, check your bill to make sure there are no surprise international charges—it helps you adjust for next time. The guide to switching back to your home line after returning covers the details.

Common mistakes and how to avoid them

• I installed an eSIM but I'm using my home line for data. This happens when mobile data is still set to your home line. Check the carrier name at the top of your screen and which line you've selected for data use after arrival.
• Data roaming was on for both lines. Each line has its own setting, and it's easy to forget. Always turn it off for lines you're not using.
• I turned off roaming for my travel eSIM and it won't connect. Travel eSIMs connect through local networks, so roaming must stay on for your eSIM (even though it's off for your home line). Turn off roaming only for the line you're not using.
• I turned off airplane mode and both lines activated. Your phone searches for all signals once airplane mode is off. Turning off roaming for your home line before takeoff is your safety net for this moment.

Is turning off data roaming enough? Other settings worth adjusting

Data roaming off is your main defense. A few additional tweaks before departure make your trip even safer and quieter on data.

• Auto-update and background downloads—turn off temporarily (OS and app updates use a lot of data)
• Photo and video backup—set to Wi-Fi only
• Auto-play on video and social media apps—turn off to keep data use low
• Where possible, download offline maps and translation data for the regions you're visiting
• If you don't want to use your home line at all, turn off mobile data for that line entirely

These steps keep your data use slow and steady, so you're less anxious about capacity. The smartphone data-saving guide has more specific tips.

How does airplane mode compare? When to use each setting

Airplane mode does prevent roaming charges, but it's less convenient for everyday travel. Airplane mode cuts cellular, Wi-Fi, and Bluetooth all at once. Yes, you stop using data, but you also can't connect to free Wi-Fi without manually turning it back on each time. You might accidentally turn it off and start roaming without realizing it. Simply turning off data roaming is a safer and more practical choice.

Setting	Stops roaming costs	Wi-Fi available	Best for
Data roaming off	Yes	Yes	People using Wi-Fi plus an alternative connection
Airplane mode	Yes	Manual re-enable needed	People who don't need the internet much
No changes	No	Yes	Only those with an international data plan

For practical travel, data roaming off plus a separate connection option strikes the best balance: no bills and internet when you need it. Note that turning off data roaming doesn't affect calls or SMS to your phone number—those are separate. Answering calls or receiving texts can still incur charges depending on your plan. Check with your carrier if you're unsure.

Can you survive on airplane mode and Wi-Fi alone? Realistic limitations

For a 2–3 day stay mainly between your hotel and a few tourist sites, airplane mode plus Wi-Fi can work. You'll have no connectivity costs and won't need to buy another SIM. It works on any phone, even those without eSIM or with SIM locks. Some phones remember to keep Wi-Fi on in airplane mode after the first time.

You can't use maps or messages while moving

The downside: without Wi-Fi, you can't do anything. You can't check maps if you get lost, contact anyone if you're running late, or call a ride-sharing app. In unfamiliar cities or when traveling at night, this can feel unsafe. Here's what each scenario looks like:

Scenario	Wi-Fi likely	What you might struggle with
Airport arrival	Often available, but may need login or have time limits	Getting directions to your hotel, staying in touch
Airport to city	Unlikely	Checking transfers, messaging about delays
Walking and sightseeing	Limited to cafes and attractions	Maps, restaurant search, translation
Restaurants and cafes	May have Wi-Fi	Payment apps, checking reviews
Your hotel	Usually available, can slow during peak times	Video calls, sending large files

Wi-Fi availability and quality vary by country, location, and time of day. This is an approximation only.

Public Wi-Fi safety

Public Wi-Fi networks may not be encrypted, and fake networks pretending to be real ones sometimes appear. Avoid entering credit card information or logging into online banking while connected. Turn off auto-connect to known networks, and check that addresses start with https. The IP and VPN guide covers these basics.

You can't receive calls or SMS to your phone number

In airplane mode, you can't make or receive calls using your phone number or send and receive SMS. If Japanese services send one-time codes via SMS, you won't get them while abroad. Before you travel, check whether you can switch to app-based or email authentication for those services. On the bright side, apps like WhatsApp, Messenger, and FaceTime work fine over Wi-Fi.

Who should consider Wi-Fi only, and who shouldn't

• Good fit: 2–3 day stays with a fixed itinerary / traveling with others who have connectivity / want to avoid all costs
• Should add connectivity: First time in a new country, traveling solo / need maps and ride-sharing frequently / want to respond to calls and messages immediately / just arrived for school or work and expect calls

Preparation for Wi-Fi-only travel

• Download offline maps and translation data for the regions you're visiting
• Take screenshots of your hotel address, booking confirmation, and flight tickets
• Agree with travel companions on meeting places and times, acknowledging that contact might be limited
• Write down emergency numbers for your destination and contact information for your accommodation and embassy
• Confirm photo backup and app updates are set to Wi-Fi only

Save important actions (payments, logins) for when you have reliable Wi-Fi. If you only need mobile data during travel, it often makes sense to use mostly Wi-Fi with a small eSIM data boost for crucial moments.

You still want internet abroad: safe connectivity options

Just turning off connectivity leaves you unable to use maps, translation, messaging, and ride-sharing apps when you really need them. The practical answer is to turn off roaming and set up a secondary connection. The four main options are:

1. Travel eSIM

It's a digital SIM that downloads directly onto your phone. Buy and install it before you travel, then simply activate it when you arrive. You don't need to swap physical SIM cards, and your home SIM stays in your phone—making it simple for first-time users. You won't have to worry about losing a tiny SIM card. Find the right plan by country, data amount, and duration using the eSIM comparison page.

2. Mobile hotspot (portable router)

Rent a portable Wi-Fi device and carry it with you. It's easy to share among multiple people and devices, but you'll need to handle pickup and returns, keep it charged daily, and carry an extra device. It's often the best choice for family and group travel.

3. International data plan from your carrier

Some mobile operators offer international data plans you can add to your existing service. You can keep using your regular phone number, but pricing, daily limits, and coverage vary by operator. Before purchasing, check with your operator for the latest terms and conditions.

4. Local SIM card (physical SIM)

Buy a local SIM card and swap it into your phone. This is best for long stays of several months or more if you want a local phone number. It requires time to buy and install the card, and you need to safely keep your home SIM.

If setup makes you nervous, the troubleshooting page covers common issues and how to fix them.

Comparing your options (quick reference)

Use this as a guide to figure out what suits you. Pricing and terms vary, so check the latest information before purchasing.

Option	Setup	Simplicity	Best for
Travel eSIM	Download and install before departure	Just your phone, nothing extra	Solo travelers, short to long trips, maps and social media focus
Mobile hotspot	Rent, pick up, return	One extra device to carry	Families, groups, multiple devices
International plan	Sign up in advance	Use your regular phone number	Calls and SMS are important to you
Local SIM	Buy at destination, swap it in	Requires SIM swap	Long stays with a local number

Think about how long you're staying and who's traveling:

• Short trips: eSIM is simplest
• Months-long stays needing a local number: local SIM
• Families or groups sharing devices: mobile hotspot
• Very short stays or layovers with light data use: your home carrier's roaming might work
• Always confirm coverage and terms first

For in-depth comparisons, see the comparison guides.

How eSIM setup works

eSIM might sound complex, but the process is straightforward. With Bloomy, here's how it goes:

1. Before you travel, confirm your device supports eSIM and purchase a plan
2. When you receive the activation link, tap it once and follow the on-screen instructions to add the eSIM
3. When you arrive, activate the eSIM and start using it

If the link doesn't work, you can usually scan a QR code or set it up manually. But the basic process is just one tap of the link. Set everything up ahead of time at home over Wi-Fi so you won't be rushed on travel day. When to activate it depends on your plan—check your purchase information. This prevents activating it too early and using up your allowance before you actually need it. Keep the eSIM line deactivated right after adding it, and turn it on when you arrive.

Dual SIM: keep your home line off and use the eSIM for data

Adding an eSIM puts you in dual-SIM mode—both your home SIM and the eSIM are active. Keep your home SIM's data roaming turned off. Then select the eSIM as the line for mobile data. Follow your eSIM's activation instructions for roaming settings.

Dual SIM: fixing charges on your home line after returning

If you're charged on your home SIM after using an eSIM, the cause is usually not the eSIM itself, but your home SIM staying active overseas. On dual-SIM phones, both your home SIM and the travel eSIM are active at the same time. Even while using the travel eSIM for data, your home SIM will also pick up local signals and may start roaming charges on your home SIM.

Another thing people often overlook is calls and SMS. If your home SIM stays active, calls and texts to your number will come through on your home SIM, and charges for receiving calls and texts vary by plan. Check with your operator before you travel.

Three settings to check before departure

What to check	Why it matters	Set it to
Home SIM data roaming	Prevent your home SIM from using data overseas	Off
Primary data line	Use the eSIM for data	Select the eSIM
Automatic line switching	Prevent switching back to home SIM due to signal	Off

Data roaming settings are per-SIM, not device-wide. Turning off roaming for your home SIM doesn't affect your eSIM's roaming setting.

On iPhone: Go to Settings → Mobile Data. Select your home line and turn off Data Roaming. Return to the list, select Mobile Data, choose your eSIM, and also turn off "Allow Mobile Data Switching." On Android: Go to Settings → Network & Internet → SIM. Select your home line and turn off Roaming. Switch the mobile data line to the eSIM. If you can't find the settings, search for "roaming" in the settings search box.

Your eSIM may need data roaming on because travel eSIMs connect through local networks. Check your purchase information for which setting applies to your eSIM.

What you'll lose if you turn off your home line entirely

Approach	Data use	Calls and texts to your number
Home SIM roaming off only	Home SIM doesn't use it	Still arrive (charges vary by plan)
Home SIM off entirely	Doesn't happen	You can't receive them
Travel eSIM (data only)	Available within plan limits	Not supported

If you need to receive SMS authentication from banks or services while abroad, decide on your approach before you travel. Options include keeping your home SIM active or setting up an alternative way to receive texts. Whether you can receive SMS abroad and any associated charges vary by plan and destination.

This section applies mainly to people keeping their home SIM active while traveling. If you're removing your home SIM or using an eSIM-only phone, skip this step. Same for people who've suspended their home line.

After landing: phone setup in four steps (while in airplane mode)

Many people turn off airplane mode as soon as the plane lands. But when you're abroad, your phone starts searching for local networks the instant you turn it off. If data roaming is still on for your home SIM, it will connect to a local partner network and start using data. Apps update and cloud sync continues in the background, so your data can be used up while you're waiting for luggage. Having a plan keeps you focused when things are hectic after landing.

Step 1: Keep airplane mode on

Don't turn it off yet. With airplane mode on, your phone won't connect to cellular networks, giving you time to adjust settings calmly. Even if others are turning it off, you'll be fine a few minutes later.

Step 2: Turn off data roaming for your home SIM

Disable data roaming on your home line. On dual-SIM phones, each line has its own settings, so make sure you're changing the right one.

Step 3: Switch to using your eSIM for data

Activate your eSIM line and select it for mobile data. You can manage line settings while airplane mode is on. If there's an auto-switch feature, turn it off to prevent unexpected charges on your home SIM.

Step 4: Turn off airplane mode and test your connection

Now you can safely turn off airplane mode. You should see the local carrier name at the top, and apps should load normally. If it doesn't connect right away, wait 1–2 minutes or toggle airplane mode back on and off.

Here's where each setting lives:

What you need to do	iPhone	Android
View your SIM lines	Settings → Mobile Data	Settings → Network & Internet → SIM
Turn off data roaming	Select the line → Data Roaming	Select the SIM → Roaming
Switch data line	Mobile Data → select the line you want	Mobile Data → select the SIM you want
Add an eSIM	Settings → Mobile Data → Add eSIM	Settings → Network & Internet → Add SIM
Check data usage	Mobile Data screen (bottom)	Data usage screen

Adding an eSIM requires internet, so if you do this at home before you travel, you only need to activate it when you arrive.

For connecting flights, family phones, and your return trip

At connecting flights, turning off airplane mode might connect you to that country's networks. If you won't use that network, keep airplane mode on or just use airport Wi-Fi. Check if your eSIM covers your connecting country before you buy. For family members and children's phones, before leaving turn off data roaming and set app updates to Wi-Fi only. Use the same approach for your return flight: keep airplane mode on and reactivate your home SIM, then turn off the eSIM before turning off airplane mode. This prevents switching mistakes.

How much data do you need? Usage estimates

Many people ask how much data they need. This table shows typical usage, but it varies based on video quality, app settings, and how you use them. If you're unsure, choose a larger amount for peace of mind.

How you'll use it	Daily estimate
Maps, search, messaging—mainly	About 0.3–0.5 GB
Social media, photo sharing, research too	About 1 GB
Video, video calls, hotspot use	2 GB or more

Available amounts, durations, and pricing vary by plan and country. Check the latest options on the comparison page.

Honest things to know before buying an eSIM

eSIM is convenient and lightweight, but there are honest points to know before you buy. Misunderstanding these could lead to buyer's remorse, so let's clarify them.

It's data-only

Travel eSIMs like Bloomy are fundamentally data-only. App-based calls and messages like WhatsApp, Messenger, and FaceTime work normally. What doesn't work is making and receiving calls using your phone number, and SMS texts. If you might need to receive calls or SMS codes from home, set up an alternative beforehand. Keep your home SIM active or have another option ready. The phone number and SMS guide has more details.

Device compatibility and SIM lock

Not all phones support eSIM. Your phone must support eSIM and have SIM lock removed. Check the compatible devices page before you travel to avoid problems when you arrive.

Choose the right amount and duration

You choose your data amount and duration when you buy. Use less for maps, social media, and messaging; more if you watch video or use hotspot. Plans and pricing can change, so check the latest details before you buy (as of June 2026).

What "unlimited" really means

We also offer unlimited plans. However, even unlimited plans have fair usage policies and speed limits after a certain amount. There may also be conditions on hotspot use. Actual speed depends on local networks, coverage, and time of day. It's not unlimited high-speed data in the absolute sense, so understand this before buying. For short trips with predictable usage, a fixed-amount plan is often clearer and more cost-effective. See the unlimited plan page for details. The unlimited eSIM guide compares when it makes sense.

When eSIM won't connect: troubleshooting steps

When eSIM doesn't connect, go through these troubleshooting steps calmly. Most issues are fixed by checking line selection and activation.

1. Confirm your eSIM line is activated and selected for mobile data
2. Check that your eSIM's roaming setting matches your plan instructions (separate from your home SIM)
3. Toggle airplane mode on and off to search for networks again
4. Restart your phone
5. If you're in a basement or building interior with weak signal, move outside or to a window. If you just landed, wait a few minutes.
6. If your eSIM doesn't appear in the line list, reconnect to Wi-Fi and try adding it again

Changing multiple settings at once makes troubleshooting harder, so try one thing at a time. If the problem persists, check the troubleshooting page or FAQ. You can also reach out via contact us. If you can't connect to Wi-Fi, open your browser to see if a login page appears. Check for password errors and connection time limits.

What's right for you? (eSIM vs. other options)

eSIM is a good fit if you

• Travel light with just your phone for leisure, work, or study
• Prepare before you leave and start using it as soon as you arrive
• Avoid swapping physical SIM cards or carrying extra devices
• Use mainly maps, translation, social media, and app-based calls

Physical SIM or other options work better if you

• Need frequent calls and SMS codes to your phone number
• Travel with a group or multiple devices (a mobile hotspot might work better)
• Your phone doesn't support eSIM (check compatible devices)
• Staying long-term and need a local number for banking and government

There's no single right answer—the best option depends on how you'll use it. When in doubt, first turn off data roaming to stop roaming charges, then choose based on your usage and you'll avoid problems. See the use-case guides for scenario-specific advice.

Checklist: before you go

• Turn off data roaming
• Review app auto-update, background refresh, and photo backup settings
• Decide which connectivity option to use (eSIM, Wi-Fi, or roaming plan)
• For eSIM: confirm device compatibility, check SIM lock status, and install before leaving
• Verify home SIM roaming is off, eSIM is set for data, and auto-switching is off
• Confirm if you need calls and SMS to your home number

With these steps done, you won't have surprise bills when traveling. When you return home, switch your data back to your home SIM. Otherwise, you might feel like you lost internet when you get home. You can delete the eSIM from settings when you're done. To find the right eSIM, use the comparison page to filter by country, data amount, and duration. You can check your balance and QR code for purchased eSIMs in your account. Learn more about preparing your phone for travel with the eSIM guide collection.