Passengers may, subject to seat availability, exchange their train ticket for an earlier departing train, upgrade or downgrade to a higher or lower class of carriage, or change their assigned seat to another seat in any carriage of the same class.
Ticket exchanges can be made at railway ticket offices provided there are no more than 24 hours remaining before the departure of the train for which the ticket is being reissued.
A ticket exchange fee, established by the carrier, applies.
When a ticket is reissued, the fare is recalculated according to the new travel conditions. If the new ticket costs more than the original one, the passenger must pay the difference. If the new ticket costs less than the original one, the passenger will receive a refund for the fare difference.