Allied Irish Banks has blamed a third party provider after customers' cards were blocked at ATMs not belonging to the bank.
The glitch left customers unable to access their cash without going to specific machines but AIB said no-one will have been left out of pocket by the breakdown.
"AIB experienced some issues with AIB debit cards earlier today and this has now been resolved. AIB apologies to customers for any inconvenience caused," a spokeswoman for the bank said.
The bank insisted that AIB cards were working fine at the bank's own ATMs but that they were being refused at other banks' machines.
It also insisted that they were being accepted in shops and online.
The technical breakdown followed delayed payments into some Bank of Ireland accounts for several hours this morning and just over a week ago when Ulster Bank was hit by the latest in a series of technical problems.
Ulster Bank promised to reimburse customers left out of pocket after salary and other payments were delayed.