Can children travel free of charge to neighbouring countries?

Adults with a ticket for cross-border travel to Switzerland or Austria can take a child or grandchild up to the age of 5 free of charge (i.e. the child must accompany the parent or grandparent). It is not possible to add children on the adult's ticket once the journey has started. 

When travelling to Switzerland or Austria, children aged 6 to 14 travel free of charge. Children must be included on the adult's ticket.