Children aged between 6 and 14 inclusive can travel free of charge on Deutsche Bahn if they are accompanied by a person aged 15 or over. This is subject to the children being listed on the ticket at the time of booking.
According to Deutsche Bahn, up to four children can travel free of charge per ticket. The children do not need to be related to one another. It is not possible to add them to the booking once on the train.
Children up to and including the age of five generally travel free of charge and do not need to be listed.
This rule also applies to Deutsche Bahn’s new last-minute long-distance travel offer. Special rules may apply to some local transport journeys. Depending on the transport authority, different regulations regarding the free travel of children may apply.
Further information:
https://www.bahn.de/service/individuelle-reise/kinder/fahrkarten-fuer-kinder/kinder-6-14-jahre
https://www.bahn.de/angebot/sparpreis-flexpreis/super-sparpreis-lastminute
https://tuenews.de/deutsche-bahn-bietet-tickets-ab-699-euro-fuer-schnellentschlossene/
tun26051102