Interrail allows you travel freely throughout Europe, however some trains require an additional reservation. In general all Suburban Trains and all Regional Trains, where you can just board the train and sit wherever you prefer, do not require any additional reservation. For High-Speed Trains and Night-Trains an additional reservation is almost always required. These types of trains usually demand a so called seat reservation. This prevents these more luxurious trains of getting over-crowded, while also giving passengers certainty of being able to sit down during their journey and thereby having a relaxed experience. When you have an Interrail pass it is required to make these mandatory reservations, preferably as far in advance as possible – because these trains can become full! Now when trains are full there are usually plenty of other options available to get to your next destination, but sometimes a particular connection is simply more convenient. Below you can find a page per participating country with an extremely detailed list of all trains; whether they require an additional reservation, whether you can make the reservation in advance and what the costs will be.
Interrail super-friendly countries (virtually all trains are free of additional costs).
– The United Kingdom
Interrail friendly countries (most trains do not require additional costs).
– Bosnia and Herzegovina
– Czech Republic
– The Netherlands