However, its third quarter results have also highlighted that despite the disruption, which went on for more than a month in some cases, customers have decided to stick with the bank.

A statement to investors said: "Customer deposits remained flat on a constant currency basis, with no significant outflows following the Group technology incident, while retail and SME balances increased marginally in the quarter."

The £175 million costs relate to waiver of interest, charges and compensation payments for customers.

To date RBS' subsidiary Ulster Bank has had to pay out the most with costs reaching £82 million; UK retail's costs reached £41 million; £25 million through group centre; £24 million through UK corporate; and £3 million through international banking.

that law firm Clifford Chance is providing 'external counsel' on what went wrong and will carry out an independent review.