This reduction follows the Office of Rail and Road’s (ORR) review which found that of the 5.8 million refunded tickets in 2019/2020, there were notable differences between the cost of processing a refund - on average less than £5 - and the allowed maximum admin fee of £10.
ORR therefore called on the rail industry to review the level of the maximum cap on refund administration fees.
The new cap of £5 comes into force when the updated National Rail Conditions of Travel is published on 2 April.
Passengers will continue to be entitled to a fee-free refund if they choose not to, or are not able to, travel because their journey has been affected by delays or cancellation.
Stephanie Tobyn, ORR director of strategy, policy and reform, said: