For the second time this month, barriers at tube stations this morning across London had to be left opened because the Oyster system has failed again according to London Underground staff members.
However, it is unlikely to cause as much chaos as the one which occurred earlier this month and which affected even the buses. Gates at train stations like in Paddington were fully functional.
A spokesperson for TFL said that the problem happened since this morning at 05:30 adding, "There is currently a technical problem with Oyster readers at London Underground stations which is affecting Oyster pay as you go cards only. Ticket gatelines have been opened to minimise any disruption to passengers whilst we resolve the problem. Oyster card readers on London Buses and on the Tram network are unaffected"
Passengers who may be charged the maximum fare of £4 will be automatically refunded; today's glitch is expected to cost TFL hundreds of thousands of pounds as thousands will travel free.
The previous incident caused 40,000 Oyster cards to break down as a result of incorrect data tables that were sent out by one of TFL's main contractors.
Earlier this week, a new report suggested that fundamental flaws in the Oyster card system would be released this October piling more pressure on TFL to either find a long term solution or can the system altogether.