Maximum fares are not overcharges. The terms of pay as you go (PAYG) make it quite clear that users must touch in and out to obtain the best fare. Maximum fares are charged to deter fraud and ensure that users validate their cards properly.
In principle, customers who do not touch in at the start of their journey are at risk of a maximum fare because they are travelling without a valid ticket. TfL calculates that between 60 and 80 per cent of the revenue raised through maximum fares would have been spent by customers if their Oyster card were validated correctly.
Approximately £10m of maximum fares are refunded to customers each year representing up to a quarter of all maximum charges.
Some four million Oyster cards are used for PAYG each month and the number of incorrectly validated journeys is falling.
75 per cent of these cards do not incur any maximum fare charges. Of the 20 - 25 per cent of cards incurring maximum fares each month, around 90 per cent incur one charge; with only a minority of users incurring more.
40 per cent of all maximum fares are incurred at National Rail stations. TfL and the Operators are examining ways of reducing this figure though it must be recognised that it is on National Rail that the greatest scope exists for fraud by customers travelling beyond the Oyster boundary.