On national lines, passengers must show an identity card before boarding the coach - a national identity card, a passport, a document issued by a public authority including a photograph which resembles the individual (driving licence, residence permit) - in order to enable the boarding personnel to check that the passenger has a ticket.
On international lines, passengers need to present a valid passport or national identity card. This verification is independent of any checks at a border control. It is the responsibility of the passenger to have the required documents at a border crossing.
