NatWest has apologised after customers complained their money had "disappeared".
Customers told the bank that money had "disappeared" while carrying out transfers on NatWest's mobile banking app.
The bank said this was due to an error causing a half-hour delay in mobile transfers. It has urged customers not to re-send any payments they have already made.
The error comes two months after a glitch on the app caused delays for more than eight hours during the Black Friday sales period.
A spokesperson for NatWest said: "We are aware that some NatWest customers are experiencing a short delay in funds leaving or reaching their accounts this afternoon.
"We apologise for any inconvenience caused."
It said the issue was resolved by 5.30pm.
