NatWest to open today after IT fault

Bank scrambles to clear payment backlog after technical problem

Branches of NatWest are to open until midday today following technical hitches that have left thousands of customers unable to withdraw cash or pay their bills.

The bank, which also had staff working until 6pm in more than 900 branches yesterday, took the unusual step of opening on a Sunday in an effort to clear the backlog. While the underlying technical issue has been fixed, the bank could not say when the problem will be fully resolved. Reports yesterday that the after-effects are expected to extend into tomorrow at least.

The technical glitch has disrupted home purchases and regular payments. Customers have found payments have gone awry and seen wages disappear. Where money has been credited to a customer's account overnight, there may be a delay in it showing up on their balance. Concerns have been raised over penalty charges following suggestions that thousands of people could be hit with fines if regular household bill payments, such as mortgages, are affected.

The issues also affect Royal Bank of Scotland (RBS), which has extended opening hours at 200 branches, and users of Ulster Bank, which extended hours at 60 branches. All three are part of RBS Group, which has apologised to customers affected by technical problems it says are now fixed. In a statement, it said it was "working around the clock" to resolve the problem fully and has pledged "no one will be left permanently out of pocket" as a result of the issue. It said the backlog was caused by a "system outage" on Tuesday.

NatWest has more than 7.5 million personal banking customers but it is not known how many people have been affected. About 100,000 Ulster Bank customers have been hit by the problem. The technical issue reportedly arose after staff tried to install a software update on RBS's payment processing system, but instead corrupted it.

One Twitter user wrote: "Due to complete on flat purchase today. All the money missing in cyberspace. Stressful enough without this, thanks #natwest."

A spokeswoman for UK Payments Administration, which oversees payments generally, said the problem did not appear to have affected other banks. But she warned that anyone expecting payments from people who bank with NatWest and RBS could encounter delays. Stephen Hester, the chief executive of RBS, which owns NatWest, yesterday apologised to customers: "On this occasion we have let them down."