CFL trains

CFL, the Société Nationale des Chemins de Fer Luxembourgeois, runs the trains, buses, trams and funicular that make up Luxembourg's public transport network. If you are travelling within the Grand Duchy, CFL is the only operator you will see, and public transport there works differently from most of Europe.

All second class public transport in Luxembourg, including CFL trains, buses, trams and the funicular, is free to use. That means Interrail and Eurail pass holders travelling second class inside Luxembourg do not need to use a travel day on their pass at all. If you are travelling first class, the picture changes: you do need to use your pass, and first class is available on CFL's regional trains.

Domestic CFL services run under two names. RegionalBahn (RB) trains stop at every station along the route, while Regional Express (RE) trains skip some stops to run faster. Neither needs a reservation, in either class, so there is no booking step to plan around for journeys inside Luxembourg.

International trains are where the picture changes again. CFL and partner operators run InterCity trains from Luxembourg City to Liège and Brussels in Belgium, and RB and RE services across the border to Koblenz and Düsseldorf in Germany and to Metz and Nancy in France. Reservations on these InterCity and cross-border services are optional, though it is worth booking ahead if you are travelling on a weekend or during a school holiday, when seats fill up faster.

The one train where reservation is not optional is the TGV to Paris. If you are taking the TGV between Luxembourg City and Paris, a seat reservation is compulsory, and this train can sell out weeks in advance. Book as early as you can, ideally around three months ahead if your travel dates are fixed, rather than assuming you can turn up and reserve at the station.

You can make reservations through Interrail's own booking system, which costs around €2 per train plus a delivery charge for paper tickets, by phone through the CFL call centre (open Monday to Friday, 07:00 to 19:00, closed on Luxembourg public holidays), or in person at a CFL ticket office. Collecting paper tickets at Luxembourg's main station carries a small pickup fee, around €5, and having them posted elsewhere in Europe costs more, around €7, so factor that into your plan if you are booking from outside the country.

For most itineraries through Luxembourg, the practical approach is simple. Do not worry about reservations for anything domestic. Treat the Paris TGV as the one exception that needs sorting out well in advance.