You have four realistic ways to get mobile data abroad: use your home plan's roaming, install a travel eSIM, buy a local SIM card at your destination, or rely on Wi-Fi alone. The cheapest and most convenient choice depends on where you are going, how long you will stay, and whether your phone supports eSIM and is unlocked.
This guide is for anyone planning a trip who wants to stay connected without a surprise bill. After reading it, you will be able to check your phone, compare the options, set up an eSIM in a few steps, and keep your data safe on public networks.
The four options compared
Prices vary hugely by country and provider, so the table compares the trade-offs rather than costs.
| Option | How it works | Strengths | Weaknesses |
|---|---|---|---|
| Home plan roaming | Use your normal number and plan abroad | No setup; you keep your number for calls and texts | Can be costly outside regions with free roaming; check daily passes and caps |
| Travel eSIM | Buy a data plan online and install it digitally | Set up before you fly; no shop visit; you keep your physical SIM for calls | Needs an eSIM-capable, unlocked phone; usually data only, so calls use apps |
| Local physical SIM | Buy a SIM card at the airport or a shop | Often good value for long stays; may include a local number | Needs a SIM tool and an unlocked phone; some countries require ID to register |
| Wi-Fi only | Use hotel, cafe, and airport Wi-Fi | No cost | Unreliable coverage; security risks; no navigation on the move |
For a trip of a few days, a travel eSIM or a roaming day pass is usually the simplest. For a stay of several weeks or a move, a local plan, either a physical SIM or a local eSIM, tends to be the better value because you may also get a local number for deliveries, banks, and booking apps.
Roaming: when it is free and when it is not
Roaming means using a foreign network under your home plan. In the EU and the wider European Economic Area (EEA), the "roam like at home" scheme lets travelers make calls, send texts, and use mobile data abroad without paying extra fees. The European Commission has extended the scheme until 2032. The scheme covers travel within the EU and EEA, so it does not apply when you travel from the EU to many neighboring countries or to other continents.
Outside regions like this, roaming rules depend on your carrier. Some carriers offer daily passes or monthly international bundles, and some include roaming for certain countries. Others charge by the megabyte, which is how large bills happen. Look up your carrier's international rates before you go, and ask whether a pass can be switched on for a single day and cancelled.
Check whether your phone works
Two things decide whether an eSIM or a local SIM will work.
- Does your phone support eSIM? Many phones from the last several years do, but not all models and regions. Look in the phone's settings under mobile or cellular data for an option to add an eSIM or a mobile plan, or check the manufacturer's support page for your exact model. Some phones sold in certain countries have eSIM disabled or require a physical SIM.
- Is your phone unlocked? A carrier-locked phone only works with that carrier's SIMs. If you bought your phone on a payment plan, it may be locked until you have paid it off. Contact your carrier and ask for an unlock before you leave, since it can take days.
Also check which network bands your phone supports if you are traveling to a different region. Most recent phones cover the common bands, but older or region-specific models may not work well everywhere.
What an eSIM is
An eSIM is a SIM built into your phone that you set up by software instead of inserting a plastic card. According to the industry body that sets the standard, it makes setup simpler because you do not need to physically insert or swap a SIM card. Most phones that support eSIM also have a physical SIM slot, which means you can keep your home SIM for calls and texts while a travel eSIM handles data.
The usual trade-off is that travel eSIMs are data-only. You can still call and message through apps like WhatsApp, Signal, or FaceTime, but you will not have a local phone number unless the plan includes one.
Set up an eSIM step by step
The exact menus differ by phone brand, but the process follows the same pattern.
- Confirm compatibility and unlock status. Do this at home, with a stable internet connection.
- Choose a plan. Pick a provider that covers your destination, and compare data allowance, validity period, and whether tethering (sharing data with a laptop) is allowed.
- Install the plan before you fly. The provider will send a QR code or an app link. Scan the code from your phone's settings menu. This needs Wi-Fi, so install it while you still have a reliable connection.
- Label the lines. Name them clearly, for example "Home" and "Travel," so you do not mix them up.
- Leave the travel line off until you land. Many plans start counting the validity period from installation or first connection, so read the terms.
- On arrival, switch lines. Set the travel eSIM as the line for mobile data, turn data roaming on for that line, and turn data roaming off for your home line.
- Keep your home SIM active for texts. Some banks send verification codes by text, so keep that line on, with roaming set to what your carrier allows.
Save the QR code and install instructions in a safe place, because some phones only allow one installation per code.
A worked example
Say you are taking a ten-day trip and your carrier offers a day pass at 10 units of your local currency per day, which is 100 units for the trip. A travel eSIM with enough data for the trip costs 25 units. These numbers are hypothetical, but the comparison is typical: a short-term data plan can cost a fraction of a roaming pass. The only way to know is to check both prices for your trip.
Avoid bill shock
Bill shock is an unexpectedly high bill after traveling. Most of it comes from background data use on a roaming connection.
- Turn off data roaming on your home line if you are using a travel plan.
- Set a data limit in your phone's mobile data settings, so it warns you or cuts off as you approach your allowance.
- Download maps, playlists, and shows over Wi-Fi before you leave, or at your hotel.
- Turn off automatic app updates on mobile data, and switch off video autoplay.
- Use airplane mode on the flight and on the first connection until you have chosen the right line.
- Ask your carrier whether it has a spending cap on international use, and whether it will text you when you reach it.
Stay safe on public Wi-Fi
Free Wi-Fi in airports, cafes, and hotels is useful, but it is shared with strangers. The US Federal Trade Commission's advice is still sound: send personal information only over encrypted connections, which means a web address that starts with "https" and shows a lock icon on every page. It also advises that a hotspot with no password, or an old WEP password, should be treated as unsecured, and that WPA or WPA2 indicates a secure network. Log out of accounts when you finish, and do not reuse passwords across sites.
A practical rule is to keep banking and sensitive accounts for your own mobile data connection, and to use public Wi-Fi for browsing, maps, and streaming. A virtual private network (VPN) adds a layer of protection, but laws on VPNs differ by country, so check them before you travel.
Common mistakes
- Buying an eSIM for a locked or unsupported phone. It cannot be used, and refund terms vary.
- Forgetting to turn off roaming on the home line. This is the usual cause of surprise bills.
- Installing the eSIM at the airport on weak Wi-Fi. Do it at home.
- Assuming "roam like at home" applies everywhere. It covers the EU and EEA, not every country nearby.
- Losing access to verification codes. If you swap your home SIM for a local one, texts to your home number will not arrive.
Frequently asked questions
Can I keep my home number if I use a local SIM or eSIM?
Yes, if your phone has dual SIM support. Keep your home SIM in the phone with data roaming off so that you can still receive texts, and use the local plan for data.
Is an eSIM safe if my phone is lost or stolen?
An eSIM is tied to your device, but the same advice applies as for any SIM: set a screen lock and a SIM PIN, and contact your carrier quickly to suspend the line. Keep a record of your phone's identifying number so you can report it.
How much data will I need?
It depends on what you use. Maps and messaging use little, while video calls and streaming use a lot. Check your usage in your phone's settings for a typical week at home and use that as a baseline for your trip.
Will this work for a long trip too?
For a longer stay, compare local plans. See our guide to packing light with only a carry-on for a trip that fits in one bag, and our advice on avoiding jet lag before a long flight.
Next steps
- Check in your phone's settings whether it supports eSIM and whether it is carrier-locked, and ask your carrier to unlock it if needed.
- Look up your carrier's roaming rates and passes for your destination.
- Compare a travel eSIM, a local SIM, and your roaming pass using the table above, and choose the best for your trip length.
- Install the plan at home on Wi-Fi, set a data limit, and switch off roaming on your home line.
