Some Barclays customers were left unable to make payments or check their balances on Monday morning as they struggled to log into their online banking services.
The bank confirmed that “a small number” of customers had been unable to log in online or via the app after being contacted by the PA news agency.
Twitter users began to report problems at around 9.50am on Monday morning, saying that they were unable to get access to their accounts.
Meanwhile, Down Detector – which collates information on major outages – said there were reports of an outage at around 9.44am.
Barclays said: “A small number of our customers are having problems logging in to their online banking and making payments on online banking and in the Barclays app.
“We apologise for this and are working to fix it as soon as possible.”
The bank said it was working to fix the issues, and advised customers to try again if they were having trouble getting into their accounts.
Customers can also use the app, contact Barclays through its automated telephone banking services or speak to the bank on the phone.
It advised customers not to try re-do any payments if they have had an error message as the payment might still go through within four hours. The bank advised customers to wait for four hours until trying again.