The technical errors caused by the software corruption at NatWest that affected its payment system has resulted in some customers paying bills twice.
NatWest is urging customers who have had duplicate payments, including mortgages and personal loan repayments taken from their accounts to get in touch with the bank so that the duplicate payments can be corrected.
NatWest says that a “small number” of customers have been affected by duplicate payments going out. It is though this is less than 100,000 customers.
An RBS spokesman said: "We apologise to any customers experiencing problems. We said last week that we expected to see a few bumps in the road for customers as we get things fully back on track.
“Any customers experiencing problems should contact our call centre or visit their local branch and we will put things right."
Two weeks ago a corrupted software update meant that customer balances were not updated and there were problems affecting millions of customers in receiving and making payments.
NatWest has fixed the problems but has been catching up on processing the huge number of transactions that were delayed by the problems.
The duplicate payments came out overnight at a time when the IT system was under pressure due to the increase in transactions to be processed at the end of the calendar month.