Customers of NatWest have been hit by an IT glitch at the High Street bank which is affecting online and app transactions.
NatWest has apologised for the problems which began at 09:00 GMT. It is payday for some customers, while others are seeking out Black Friday offers.
The issue has affected transfers between accounts.
NatWest said there was no problem with debit cards, credit cards, ATMs, telephone and branch banking services
The transfer issue has proved a particular problem for asthmatic Tim Pitman who moved money hoping to pay for a prescription.
The 49-year-old singer, from Glastonbury, said he had to borrow money from a friend to pay at the chemist, which was a 15-minute drive away.
He said NatWest should have been clearer with customers who were affected.
Some of those customers include people hoping to get a deal during Black Friday promotions.
A spokesman for RBS, which owns the NatWest brand, said: “We are aware that some customers are experiencing intermittent issues accessing our mobile and online banking.
“We apologise to customers for the inconvenience and are working hard to fix the problem. There is no impact on debit cards, credit cards, ATMs, telephone and branch banking services – customers can continue to access these as normal.”
Research from Which? released earlier this week found the banking industry suffers around five IT failures each week typically, shutting millions of customers out of accounts and making payments.