Rail travellers "do not trust" the ticket system, a passenger group chief has told MPs.
Some travellers were not sure they had been sold the right ticket and were "just not confident" about the system, said Passenger Focus passenger issues head Mike Hewitson.
A number of passengers buying particular tickets were unaware that they could travel on that train and that train alone, he told the House of Commons Transport Committee.
He said: "Passengers don't trust the ticket structure. If you ask passengers they say they are not sure they have been sold the right ticket - they are not confident."
Campaign for Better Transport chief executive Stephen Joseph told the committee: "The fares system needs fundamental reform. We need a system which is simpler, fairer and cheaper.
He added that there were groups of people who were not getting value from the fares system, particularly those working part-time.
"There are also problems on some of the inter-city routes in the way that advance tickets are sold."
David Mapp, commercial director of the Association of Train Operating Companies, told MPs that he did not think the fares system was fundamentally broken, but he agreed that there were aspects of the system that could be improved.
He added that there was now far more information about exactly which fares were available and this was allowing travellers to make "informed choices" about the right ticket to buy.