Barclays has apologised to customers after technical problems caused disruption to services and payments over the weekend.
The bank said the issue had been resolved on Sunday morning and delayed payments processed.
Barclays had previously said affected customers could see an outdated balance with payments made or received not showing.
On Sunday morning, a Barclays spokesperson said: “The technical issue impacting our customers on Friday and Saturday has been resolved and delayed payments processed.
“Customers can use our app, bank online, call us, use their cards and withdraw cash. We are working on bringing balances up to date for some of our customers and addressing any outstanding issues.
“We are very sorry for any disruption and will ensure that no impacted customer is left out of pocket.
“We are keeping our call centres open for longer this weekend and we will be proactively contacting customers who may be vulnerable.”
The outage was caused by a technical issue and is not believed to be related to a cyber attack, it is understood.
Friday’s outage coincided with payday for many workers and the deadline for self-assessment tax returns.
HMRC said it was “working closely” with Barclays to minimise any impact on those submitting their self-assessments and that HMRC services are “working as normal”.
According to outage tracker Down Detector, thousands of customers claimed they were experiencing issues with mobile banking, online banking and paying bills on Saturday.
Frustrated customers took to social media to complain about the glitch, with one mother saying she was “embarrassed” to put her food shopping back.
“Due to Barclays I’m left without money. Had a food shop due for delivery this morning which now will get cancelled and leave my four kids with no food. It’s a joke as [it is] my money,” one X user claimed.
Another claimed: “Well I’ve just had to put all my shopping back in Tesco never been so embarrassed in my life .. as can’t access my own money.”