NatWest has apologised after thousands of customer accounts were mistakenly showing debit card purchases twice.
The error meant some accounts were showing lower available balances than they should.
Around 112,000 NatWest customers are thought to be affected, with the vast majority of customers being unaffected by the glitch.
While for most customers, there will be no impact, the bank has said it will ensure that anyone affected is not left out of pocket as a result.
In a service status update for its customers, the bank said: “Some customer accounts are showing debit card purchases twice, and in certain cases their available balance will be lower than it should, we’re really sorry for any inconvenience.”
One Twitter user told the bank: “Any idea what’s going on with this double transaction stuff all my money has been taken out my bank leaving me with nothing.”
A NatWest spokesperson said: “We are aware that some NatWest customers’ accounts are showing some Visa debit card purchases twice, and in certain cases their available balance will be lower than it should.
“We are working to fix the problem, and will ensure that no customer is left out of pocket.
“Our customers can be assured that payments to retailers/merchants have only been made once, so there is no need to contact them. We apologise for any inconvenience this has caused.”
Customers can contact NatWest about the issue using private message on social media, via the app or by using its online chat service.