AIB has apologised after letters were sent to customers informing them of large increases to their mortgage repayments after they were reportedly under-charged for years.
The banking blunder affects some tracker loans transferred from Ulster Bank, which appeared to have been miscalculated. This would have led to some customers paying up to an additional €600 every month.
The Irish Independent reported that letters were sent to customers this week informing them of the increases to their repayments from October.
Responding to the story, an AIB spokesperson said affected customers will not have to take any immediate steps, and the bank will engage with them to take "corrective action".
It is not known how many of the 32,000 customers whose loans were transferred from Ulster Bank are impacted.
The Central Bank said it has been in contact with both AIB and Ulster Bank over the issue.
The regulator said it expects both institutions to rectify any errors or breaches to ensure customers are treated fairly.
