NatWest has been plagued by a glitch in its software that left customers unable to update their balances and make payments for several days.
The IT problem began late on 19 June, when customers' balances failed to update correctly, making it impossible for many customers of NatWest, RBS and Ulster Bank to access their accounts online or through ATMs, and stopping direct debits and standing orders from processing.
Read ZDNet's round-up of the banking failure here:
A technical fault has affected transactions for a number of Natwest, Ulsterbank, and RBS customers, leaving some unable to use on and offline banking services.
Around 1,000 NatWest branches opened early on Friday morning, to serve customers affected by a continued glitch in the bank's systems.
NatWest is facing compensation claims and questions about the IT glitch that hit its systems last week. Image credit: NatWest
NatWest hopes to have most of its customers' account balances rectified on Monday, the bank said on Sunday as the effects of a massive technical failure entered their sixth day.
After a software bug caused widespread payments chaos last week, RBS faces regulatory scrutiny and compensation claims from customers who incurred charges.
The problems that have hit NatWest and RBS customers across the country highlight the need for the financial industry to be more open about its IT, and cloud providers may hold the answer.
Bank of England governor Mervyn King has called for the Financial Services Authority to carry out a detailed investigation into the massive NatWest outage.
An unknown number of NatWest, RBS and Ulster Bank customers are continuing to experience problems with payments into and out of their accounts, with no timeline for when systems will be completely back to normal, RBS has warned.
The systems meltdown that hit NatWest customers is an accident waiting to happen to many UK banks, analysts have warned, as financial institutions try to balance cost-cutting with the need to modernise their IT.
The banking group has had to set aside £125m following tech problems in June that saw computer systems unable to refresh customers' bank balances
A parliamentary committee has told banks they must check their IT systems following the outage at RBS Group in June, which left millions of customers unable to update their bank balances.
The banking group's 'technology incident' back in June has now cost a total of £175m, much of which has taken the form of compensation payments to affected customers of NatWest, RBS and Ulster Bank.