Your first 4 seat reservations are free. You get 4 seat reservation credits with your DiscoverEU Interrail Pass, and you can use them to book these reservations. After you've used your credits, you pay for any extra seat reservations yourself. How seat reservation credits work
Note: if you take part in DiscoverEU through a local organisation, you may not receive seat reservation credits. In that case, the information about credits doesn't apply to you.
Which trains need a seat reservation?
Some trains, mostly high-speed and night trains, need a seat reservation. On these trains, your Pass isn't valid without one, and you need to show both your QR code and your seat reservation ticket. The Planner shows which trains need a seat reservation. How ticket inspection works
Want to avoid seat reservations? Slower regional trains usually don't need one. In the Planner, tap Filters and turn on No seat reservations required. How to avoid seat reservations
High-speed trains
High-speed trains often need a seat reservation, especially in France, Italy and Spain. Popular routes, and international trains to and from France in particular, can sell out quickly, especially in summer.
When to book: as early as possible.
Important: if a seat reservation is required and you board without one, you could be fined or asked to leave the train at the next station.
InterCity trains
InterCity trains run between Europe's main towns and cities. Most of them don't need a seat reservation, so your Pass is all you need. In busy periods, though, you might not find a free seat. If having a seat is important to you, book a seat reservation.
A few InterCity trains do need a seat reservation, so always check the Planner when you plan your trip.
When to book: usually the day before or on the day itself. If your plans are already fixed, booking earlier is fine too.
Regional trains
Regional trains usually don't need a seat reservation, and on most of them you can't make one. Just get on and find a seat.
Night trains
Night trains always need a seat reservation, even if you only want a seat. The price depends on the train and how comfortable you want to be: a seat is the cheapest, a couchette (a bed in a shared compartment) costs more, and a sleeper cabin costs the most. Beds can sell out weeks in advance, so book early. Interrail's seat reservation fees
Using your credits? You can only use them for a seat on a night train, not for a couchette or sleeper. How seat reservation credits work