Bank Of Ireland tonight apologised for a computer glitch that affected the accounts of 60,000 customers.
The bank's computer systems duplicated electronic payments in an error that affected 160,000 transactions. Instead of making payments due yesterday, its system copied the payments made on the previous day.
"The bank is now in the process of correcting this by a reversal of the duplicate payments and ensuring that those not processed on March 30th are done so," said a spokeswoman.
"The bank will ensure that there are no fees or interest implications for customers as a result of this error."
She said customers would be fully refunded for any improper payments by tonight but added that the trawling of accounts for any improper fee or interest payments would take longer.
Bank of Ireland has set up an internal investigation to ensure no recurrence of the error.