Bank of Ireland is to refund €3 million to users of its cash machines after it emerged that their accounts were debited for incomplete transactions.
The mistake came to light as part of an internal monitoring process and affects up to 14,000 Bank of Ireland customers and 29,000 customers of other banks using Bank of Ireland ATMs.
The Financial Regulator has been informed.
The error occured when people making a withdrawal at the ATM did not take the cash. The banks said the installation of anti-fraud measures caused the system response of automatically prompting a refund not to occur for these particular transactions. The accounts were still debited for the transaction.
Some €1.3 million will be returned to the bank's customers this week, while €1.7 million will be refunded to non-customers. The bank said it is working with other banks to process these refunds.
In a statement, the bank apologised for the error and said procedures had been enhanced since last year for handling incomplete transactions.
A spokeswoman for the bank said today that "fair value interest" would be paid to customers on the amounts refunded.