Transport tickets on your phone: what works without a connection

Tapping in with the phone you pay with

In cities where the barriers take contactless cards, your phone works like one. Transport for London puts it in a sentence: using a mobile payment to pay as you go is the same as using a contactless card, with Apple Pay and Google Pay both accepted. Like a payment in a shop, the tap is between the phone and the reader, so it does not need mobile data.

London's rules show what to watch for anywhere that charges by journey. Always touch in and out with the same device, because TfL counts your phone and your watch as different devices: touch in with an iPhone and out with an Apple Watch and you can pay more. Keep other contactless cards away from the phone to avoid card clash. And keep battery: TfL warns that if the device runs out, you pay the maximum fare.

TfL also says many contactless cards issued outside the UK work for pay as you go, while your card issuer may charge overseas fees. That is a question for your bank, not for the barrier.

Express Mode: the barrier without unlocking

On iPhone, Express Mode lets some transit cards and payment cards be used without waking or unlocking the phone, and without Face ID, Touch ID or a passcode. Apple says it is supported in some regions, and that in those regions it is turned on by default when you add an eligible card. Apple also says power reserve keeps some Express Mode cards working for up to five hours when the iPhone needs charging, but not if you switch it off yourself.

To choose which card the barrier takes, open Wallet, tap the card, tap the More button, then Card Details, then Express Transit Settings or Express Mode. Apple's advice for anything else is to check with the local transport agency, since it lists hundreds of markets and not the details of each one.

Train tickets stored in the operator's app

A ticket you bought in an operator's app is often saved in the app itself. Deutsche Bahn is explicit about its mobile tickets in DB Navigator: the ticket is saved on your phone, so you can always show it, even with no mobile reception. DB is just as explicit about the shortcut people try: a printout of the mobile ticket, for example in the form of a screenshot, is not valid.

Rail passes can be stricter. The Interrail help centre says a mobile pass must go online at least once every 24 hours or it counts as inactive, which our guide to Wi-Fi on trains in Europe covers along with the trains that offer Wi-Fi to do it.

Since rules differ by operator, run the same test with any ticket app before the trip: switch on airplane mode, open the ticket and see whether it appears.

What still needs data on the platform

• Buying the ticket, or changing it after a missed connection.
• A ticket that arrives by email or as a link, until you have opened and saved it.
• Delay alerts, platform changes and the live departure board in the operator's app.
• Seat reservations and the regular check-in that some passes require.
• Journey planning, unless you have downloaded the map beforehand.

Station Wi-Fi can carry some of this, but it is often a login page away from working, and it is no use once the train pulls out.

Crossing a border by train

A long-distance train can cross two or three countries in an afternoon, and your phone changes network with it. A single-country eSIM only works in its own country, so on a cross-border trip it stops at the border, as our guide on crossing a border with a country eSIM explains. Snoozim's Europe pack covers 33 countries on one eSIM, which is the simpler setup for a rail trip through several of them.

Whichever plan you use, buy the tickets and open them once while you are still on Wi-Fi. Then the stored ticket, the contactless tap and the downloaded map work on their own, and the data is only needed for the live part: delays, changes and the next booking.