Europe by train: sorting your phone data before you go

Notes from planning a two-week loop through Paris, Barcelona, Milan and Zurich, written so I don't make the same mistakes twice.

The first time I did a rail trip across Europe I assumed my phone would "just work". It did, sort of. Then the roaming texts started arriving, and by day four I was standing outside Milano Centrale hunting for a café with Wi-Fi so I could find my hostel. This is the checklist I now run through a week before any multi-country trip.

1. Work out whether you actually pay for roaming

If your SIM is from an EU country, the EU's "roam like at home" rules mean you can use your normal allowance in other EU and EEA countries without extra charges, within fair-use limits. The official summary is on the Your Europe roaming page.

Two big gaps catch people out:

• UK SIMs. Since Brexit, the EU rules no longer cover UK networks, and several of the big carriers charge a daily fee to use your allowance abroad. Check your own plan before you assume.
• Switzerland. It isn't in the EU or EEA, so even an EU SIM can get expensive the moment the train crosses the border at Domodossola or Basel. On my route, Zurich was the leg that would have cost the most.

If either applies to you, a regional travel eSIM is usually simpler than juggling daily passes.

2. Check your phone before you buy anything

• eSIM support: dial *#06#. If you see an EID number, your phone has an eSIM chip.
• Carrier lock: phones bought on contract are sometimes locked to one network. Ask your carrier, or look under the SIM or carrier-lock section of your settings.
• Coverage list: make sure every country on your route is on the plan, Switzerland and the UK especially, since some "Europe" plans leave them out.

3. Be honest about how much data you use

People tend to overbuy. Rough real-world numbers from my own trips:

• Maps navigation, messaging and train apps: well under 1 GB a week if you download offline maps first.
• Social media scrolling with video: easily 1 to 2 GB a day.
• Streaming on the train: Netflix says HD can use up to about 3 GB an hour, so download episodes on hotel Wi-Fi instead.
• Hotspotting a laptop for work: plan for several GB per working day.

For two weeks of maps, booking apps and photo uploads, 10 GB was plenty for me. If you work from the road, go bigger.

4. Install the eSIM at home, not at the airport

This is the single best habit I've picked up. Install the eSIM the evening before you leave, on your home Wi-Fi, and leave it switched off until you land. Then on arrival:

1. Turn on the travel eSIM line and set it as your mobile data line.
2. Switch data roaming on for that line (travel eSIMs nearly always need this).
3. Keep your home SIM active for calls and texts if you want bank codes, but turn data roaming off on it so it can't quietly run up charges.

Screenshot the QR code and the manual activation code too. If the install fails, you can type the code in by hand.

5. Paying for it

I hold a bit of crypto, so this time I paid for my plan on CryptoeSIM.io, which takes BTC, ETH, USDT, Monero and a few hundred other coins, plus normal cards. It didn't need an account or ID, and the QR code arrived by email after the payment confirmed. If you want a deeper comparison of coverage, unlimited versus GB plans and what to expect on price, this Europe eSIM guide covers it country by country.

Whatever you use, compare the plan price with your own carrier's daily roaming fee multiplied by your trip length. For a two-week trip the difference is usually obvious.

The short version

• EU SIM? You're mostly covered, except Switzerland.
• UK SIM? Check your daily roaming fee before you go.
• Download offline maps and shows on Wi-Fi.
• Install the eSIM at home, enable data roaming on it on arrival, and turn roaming off on your home line.

Do that and the only thing you'll be hunting for outside Milano Centrale is a decent espresso.