NS trains

NS, Nederlandse Spoorwegen, is the Netherlands' national railway operator, running the country's domestic Intercity and Sprinter network from hubs at Amsterdam Centraal, Rotterdam Centraal, and Utrecht Centraal. A separate subsidiary, NS International, runs the country's international and high-speed services in partnership with foreign operators. That split matters. It's the international side, not the domestic one, where reservation rules and supplements actually apply.

Domestic Intercity (IC) and Sprinter trains don't need a reservation, and neither does an Interrail or Eurail pass holder travelling between Dutch cities. The one domestic exception is Intercity Direct, the faster service linking Amsterdam Centraal, Schiphol Airport, Rotterdam Centraal, and Breda. A supplement applies on the Schiphol to Rotterdam section if you're using it for a domestic trip. Watch for it. It's easy to miss if you're used to reservation-free Dutch trains.

NS International's high-speed services carry the reservation rules that actually catch people out. Eurostar, running to Brussels, Paris, and London, requires a compulsory reservation every time. These trains can sell out on popular dates. Book as early as you can. ICE services to Germany need a reservation during the summer peak, from late June to the end of August, and are strongly recommended for the rest of the year even though they're not compulsory then. Don't assume an Interrail or Eurail travel day alone guarantees you a seat on either of these.

EuroCity and EuroCity Direct trains to Brussels, jointly run with Belgium's SNCB, work differently again: reservations aren't available on these at all, so there's nothing to book, just activate your travel day and board. Night trains are a separate case. ÖBB's Nightjet services from Amsterdam to Innsbruck, Vienna, and Zürich all require a reservation for your seat, couchette, or sleeper, and the Amsterdam to Prague European Sleeper service does too.

Interrail and Eurail passes are valid on NS's domestic network and on most of NS International's partner services, but pass validity and reservation requirements are two different things. Check both before you travel, not just whether the pass covers the operator. Because the Netherlands is a eurozone country, any prices you see for NS or NS International tickets and supplements will be in euros, so there's no need to convert them from anything else.

Amsterdam Centraal, Rotterdam Centraal, and Utrecht Centraal are the three stations to know as a visitor, since almost every domestic and international NS service passes through at least one of them. If you're changing between a domestic Sprinter or Intercity and an NS International service, allow a proper connection window rather than the bare minimum, especially at Amsterdam Centraal, where platforms for international departures can be a longer walk from the concourse than the domestic ones.