NatWest and its parent company RBS are grappling with the latest blow to their brand reputation amid widespread reports of customers having their debit and credit cards declined in shops across the UK on what was also one of the busiest online shopping days of the year.
The cause of the technological meltdown is unclear, with speculation ranging from suggestions of a cyber attack to a repeat of the same glitches that caused chaos for millions of customers for days last year. The systems meltdown in 2012 left the bank unable to update customer balances while other customers faced difficulties in paying bills and moving home.
The potentially serious consequences of the latest technical problems were underlined by the nature of messages posted on Twitter by angry customers after reports began to filter through in the early part of the evening that cards were being declined in shops and at other premises.
"Im leaving you #natwest I've had enough of this dis functional relationship @natwest_help," tweeted one.
Another tweeted: "Great stuff, #NatWest. Leaving your customers stranded YET AGAIN!!! Time to find a decent mattress!!"
NatWest's press office appeared to be as much in the dark about the cause of the problem as any of their customers, referring queries to the bank's Twitter account and releasing a two-sentence statement.
"We are aware of the technical issues being experienced by customers and are working to get them fixed urgently. We apologise to customers for the inconvenience caused."
The chaos comes as RBS has already been battling to fend off other serious problems. Its new boss admitted last month that the reputation of the bailed-out institution had been seriously damaged by allegations that it was deliberately wrecking small businesses in pursuit of profit.
Some £450m was expected to go through the online tills on Monday as the Christmas shopping season took off.
Julian Wernick, a NatWest customer who contacted the Guardian, said he had waited for close to an hour on NatWest's customer helpline, yet had been able to get through on an option for sales within minutes. "That just about tells you where their priorities are at the moment,".
