Free public transport normally ends at Luxembourg's border. Cross-border commuters and travellers need a valid cross-border ticket or subscription for the paid section of the journey.
The invisible fare line
The ticket must exist before the free part ends
Inspectors can ask for a valid ticket no later than the last train or bus stop inside Luxembourg before the border. Buying only after the vehicle enters another country can be too late.
Bus and train products are not interchangeable by guesswork
RegioZone products cover several cross-border bus lines, while international or regional rail journeys use their own tickets. Search the exact route in Mobiliteit or CFL go instead of choosing a ticket because its destination country looks right.
First class is a separate border before the border
Moving into first class creates a paid journey even when the train remains in Luxembourg. Domestic first-class tickets are not automatically valid on international lines, so both the class and the geography matter.
Know the three named station exceptions
Second-class travel is free to and from Athus, Audun-le-Tiche and Volmerange-les-Mines. These nearby stations sit just outside Luxembourg but are explicitly included in the free arrangement.
A return journey may use different products
A trip from Luxembourg City to a border town can be free while a later connection onward is paid. Save the outbound and return routes in the planner separately, especially when changing between rail operators.