NatWest Group PLC has apologised to customers after its online and mobile banking services suffered outages on Tuesday morning.
The bank said it is looking into the issue after receiving a swathe of complaints from customers on X, formerly Twitter.
“We are aware some customers are having issues with logging into the app and online banking,” NatWest posted on its “help” account on X.
“This is being investigated with the highest priority.”
People complained they were unable to access their bank accounts, meaning they could not check balances or transfer money.
One social media user said their local bank branch had been closed so they were unable to do their banking in person instead.
Another said they needed to access their money in order to pay bills.
According to the website DownDetector, problems were first reported at about 0600 BST, and peaked at about 0730 BST on Tuesday.
On the NatWest website, a service status update later on Tuesday morning showed there was service disruption to both the mobile app and online banking.
“We’re sorry for any inconvenience caused and we’re working hard getting everything back up and running for you,” it said.
“If you need to complete a transaction you can continue to do this using our telephone banking service or alternatively you can visit one of our branches or ATMs.
“If you are looking to make a payment with us today, please consider sending money another way.
“You can still use your debit or credit card to make payments and get cash from ATMs, branches and the Post Office.”
On Twitter, NatWest asked customers to send a direct message if they have a specific banking need.
NatWest shares rose 1.2% to 311.20 pence each on Tuesday morning in London.