The travel department for the Welsh Assembly has confirmed that passengers could be waiting up to five years for an electronic card payment scheme to be rolled out onto trains, due to the set up costs involved.
The Welsh government's national transport plan had promised a scheme similar to the Oyster card in London, which was introduced to the capital almost ten years ago, would be rolled out by 2014.
A spokesperson for the government blamed the renewal of its current rail franchise contract.
She said: "Trials of the Wales Travel Card are currently underway on buses with roll out anticipated to start in 2013 - a year before the National Transport Commitment of 2014.
"Our ambition is to have the cards accepted on rail services at the earliest opportunity. However given that there will be set up costs for the rail franchise operator and that the current franchise ends in 2018 it is most probable that the cards will only be fully functional when the new franchise is in place."
Arriva currently runs the train franchise for the Welsh Assembly.
Lee Waters, director of the transport charity Sustrans Cymru, told the BBC that the delay is not surprising.
"The Welsh transport system is very complicated," he said.
"This is a simple idea - it makes a lot of sense and it works in London but it works there because the government controls the buses and the trains.
"In Wales, there is complete fragmentation and it is very difficult for the Welsh government to translate a simple idea into action."
Transport for London recently revealed that all buses in the Capital now accept payment via credit and debit cards using Near Field Communications technology. It is expected that that the technology will be rolled out onto the tube network during 2013.