An RBS spokesman said: “We are aware of an issue which has resulted in a delay to payments and direct debits being applied to some customer accounts. We have fixed the underlying issue, we apologise for the inconvenience caused and we are working flat out to get these payments updated for our customers no later than Saturday.
“To any customers concerned about the implications of this issue, we advise them to come into a branch or get in touch with our call centres where our staff will be ready to help. We will ensure no customers are left out of pocket as a result of this issue.”
The group could not confirm how many customers had been affected, but said it was not all accounts.
In June 2012, a software upgrade at an IT centre in Edinburgh, where RBS is headquartered, resulted in customers being unable to access their money or pay bills by direct debit or standing order.
To deal with the chaos, more than 1,000 RBS branches extended their opening hours, with banks serving customers on Sundays for the first time (picture above).
RBS, which is 82 per cent owned by the taxpayer after being bailed out by the government in 2008, promised that customers would not be left out of pocket, with overdraft fees and charges incurred by customers automatically waived.
At the time, the banking group set aside £125m in compensation. In 2014, it was fined £56m by regulators, the Financial Conduct Authority and the Prudential Regulation Authority, for the failure.
RBS says it has invested hundreds of millions of pounds in updating its IT systems.