Santander has apologised for a “technical problem” which left some customers unable to make payments online or buy food at the supermarket on Saturday, although the bank said its services had returned to normal by the late evening.
Customers have reported problems with the bank’s telephone, branch, online and card services.
Consumer organisation Which? said some people had reported not being able to make payments for several hours.
The bank has advised customers they can access cash from other banks’ ATMs.
A statement on the bank’s website said: “We’re sorry a technical problem is still affecting our services.
“If you need help, some of our branches will be open until 6pm today and between 10am to 12pm on Sunday. Cash is available at other banks’ ATMs. Please check back here for further updates.”
It also tweeted: “We’re sorry that a technical problem is affecting our services, our teams are working hard to fix it.”
Gareth Shaw, head of money at Which? said: “These technical issues will be causing stress for many Santander customers – with people reporting that they have been unable to make online payments or in some cases purchase food in their local supermarket.
“Customers can incur fines, penalties and fees when they’re not able to access their finances, so the bank must offer compensation to all those who have been impacted in this way.
“These problems demonstrate why it is vital that banks invest to ensure their systems are up to the task of protecting their customers’ accounts and maintaining the services they rely on.”
It is unclear how many customers were affected.
In a statement on Saturday night, Santander said all its banking services were back to working as normal. The statement continued: “We are very sorry for the inconvenience you’ve experienced today. If you need help, some of our branches will be open on Sunday from 10am to 12pm. We’ll publish a list of these tomorrow.”
The bank had earlier assured customers that “no one will be out of pocket” as a result of the glitch.