Barclays Bank is battling to fix technical problems bedevilling its online and mobile services on one of the busiest days of the Christmas shopping season.
Customers took to twitter to complain about the crash, which has locked down access to Internet and mobile transactions.
Many were unimpressed by Barclays' customer service levels as they struggled to find out where the fault lay.
The breakdown in systems is the third in as many weeks for the bank, which has experienced an upsurge in technical problems over the past month.
The bank posted a tweet mid-morning to warn customers of the latest issue.
Three hours later, the bank said normal service was being restored.