Booking is obligatory. If the date of the homeward journey cannot be fixed before departure, the ticket will be an open return ticket. In this case, the traveller must book the return ticket in a Eurolines office not later than10 days before the date of the home journey. Normally, the traveller is charged a service fee of DKK/ SEK/ NOK 50 or EUR 7 per ticket per person. The size of this fee may not be the same in all countries. Particularly in high season, Eurolines recommends that travellers book both outward and home journey at the same time. Customers are only guaranteed a seat if a reservation is made.