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Sorting your connectivity before you fly is one of the highest-value things you can do in the last 48 hours before a trip. Roaming charges add up, airport SIM queues are slow, and relying on hotel Wi-Fi is miserable. Here is how to land connected from the moment your wheels touch down.
1. Get an eSIM before you leave
The single best upgrade to your international travel experience is switching to an eSIM for data abroad. An eSIM is a digital SIM you install on your phone before departure, with no physical swap and no queuing at an airport kiosk.
Airalo is a widely used eSIM provider for travellers, with local and regional plans covering more than 200 countries. You purchase and install the eSIM digitally, activate it on arrival, and you are online before you have left arrivals.
To understand how eSIMs work and whether your phone supports one, see our eSIM explainer and our eSIM device compatibility guide.
2. Check your phone's eSIM compatibility
Most smartphones released from 2019 onwards support eSIM. To check on iPhone, go to Settings, then General, then About, and look for 'Available SIM' or 'eSIM'. On Android the path varies by manufacturer, but Settings, then Connections, then SIM Manager is a common location.
Two things catch people out. A handset can support eSIM and still be carrier-locked, which prevents a second profile from activating, so check both. And a phone bought second-hand may have an eSIM profile from a previous owner still installed, which is worth clearing before you travel.
If your phone does not support eSIM, a local SIM on arrival is the fallback, available at airport convenience stores and phone shops in most destinations. Our eSIM versus SIM card comparison sets out the trade-offs.
3. Turn off data roaming before you land, unless you have a plan
If you do not have an eSIM or a roaming plan sorted, turn data roaming off in your phone's settings before you land. Roaming charges can be triggered automatically the moment your phone connects to a foreign network, even if you are not actively using it.
Go to Settings, then Mobile Data, then Roaming, and switch it off.
You can still use Wi-Fi. Just do not let your phone connect to a foreign carrier without an explicit plan in place. Our Wi-Fi versus mobile data abroad guide covers when each makes sense.
4. Download offline essentials before departure
An eSIM or data plan is your primary connection, but having offline backups is good practice:
- Maps: download offline maps for your destination before you leave home
- Translation apps: download offline language packs rather than relying on a live connection
- Your itinerary and booking confirmations: screenshot or save to a note that works offline
- Emergency contacts: your country's embassy number in your destination, and your travel insurer's emergency line
- Your eSIM activation instructions: these are the one thing you cannot look up if the eSIM has not activated
5. International calling
Data is sorted, but what about calls? The main options:
- Messaging apps such as WhatsApp, FaceTime, and Signal make calls over Wi-Fi or mobile data, and work anywhere you have connectivity
- Your eSIM plan may include calls and SMS, particularly on local plans. Check what is included before you buy
- Roaming add-ons from your home carrier are worth comparing if you specifically need to make local calls on your usual number
One practical point that is easy to miss: if you rely on SMS two-factor authentication for banking or email, work out how you will receive those codes before you leave. An eSIM data plan does not carry your home number, so keep your primary SIM active for SMS even while data runs over the eSIM.
6. How much data will you need?
Most travellers overestimate. Maps, messaging, and email are light. Video streaming and cloud photo backup are not, and automatic photo backup over mobile data is the most common reason a plan runs out early. Turn cloud backup to Wi-Fi only before you fly.
Our guide to how much mobile data you need for two weeks works through realistic usage.
7. Airport connectivity on arrival
Most major international airports offer free Wi-Fi. For longer layovers, or arrivals at airports with limited free Wi-Fi, your eSIM will already be active, which is another argument for sorting it before departure.
A quick pre-departure connectivity checklist
- eSIM purchased and installed
- eSIM activation instructions saved offline
- Handset confirmed eSIM capable and not carrier-locked
- Data roaming setting understood, on if using an eSIM or roaming plan, off otherwise
- Cloud photo backup switched to Wi-Fi only
- Two-factor authentication method confirmed to work abroad
- Offline maps downloaded
- Booking confirmations saved offline
- Emergency contacts saved
For the wider pre-trip picture, see our smart traveller connectivity checklist.
Frequently asked questions
What should I sort out before flying to stay connected abroad?
Install an eSIM while you still have reliable wi-fi, confirm your phone supports it, decide what your roaming settings should be on landing, download offline maps and documents, and make sure your two-factor authentication still works without your home network.
Can I install an eSIM after I land?
Installing usually requires an internet connection, so you would need airport wi-fi to do it. That is why installing before departure is the standard advice: it removes a dependency at exactly the moment you are least able to troubleshoot.
Will my phone work with an eSIM?
Most recent flagship and mid-range handsets support eSIM, but coverage is not universal and some regional model variants differ. Our eSIM device compatibility guide covers how to check your specific device.
Should I turn off data roaming when I land?
If you have an eSIM or a local plan covering your data, yes, turning off roaming on your home line prevents your home network from being used unintentionally. If you are relying on your home plan's roaming allowance, leave it on.
How much mobile data will I actually need?
It depends heavily on whether you stream, navigate constantly, or upload photos and video. Our guide to how much mobile data you need for two weeks breaks this down by usage pattern.
What should I download before I leave?
Offline maps for the areas you will visit, booking confirmations and travel documents, any translation language packs you need, and boarding passes. Anything you would struggle to retrieve without a connection is worth having stored locally.
How do I receive two-factor authentication codes abroad?
This is the step most often missed. If your codes arrive by SMS to your home number and you disable that line, you may lock yourself out of your own accounts. Move critical accounts to an authenticator app before you travel.
Is airport wi-fi enough to get started?
Sometimes, but it is inconsistent, often requires a local phone number to register, and is not a good thing to depend on after a long flight. Arriving already connected avoids the problem entirely.
Is an eSIM better than a physical SIM card?
They serve the same purpose with different trade-offs around setup, switching, and keeping your home number active. Our comparison of eSIMs versus SIM cards covers where each makes sense.
Should I just rely on wi-fi instead of mobile data?
For some trips that works, particularly city breaks with heavy cafe and hotel coverage. It becomes unreliable the moment you need navigation, transport updates, or a booking confirmation while moving. Our comparison of wi-fi versus mobile data abroad sets out the trade-off.