Online personal finance magazine This is Money reported that Abbey customers who paid for goods at the till over the weekend or used ATMs found that they had been doubly charged. The lender told the site that it was aware of the problem, and was reimbursing its customers.

Abbey said: We apologize for any inconvenience caused, and will ensure that no customer is financially disadvantaged as a result of this error. Duplicate transactions will be automatically reversed overnight.

Customers need not take any action. They will have funds returned to their accounts and backdated, with any charges incorrectly incurred automatically refunded.