The glitch allowed customers to withdraw and transfer more than what was in their accounts on Tuesday.
Bank of Ireland has apologised after a technical issue with its services led to some customers withdrawing or transferring more than what was in their accounts.
The bank said its app and and online services are working again and any transfers or withdrawals will appear in their accounts during the day.
It encouraged any customers who find themselves in financial difficulty as a result of the fault to get in touch.
Large queues built up at the bank’s ATMs in parts of the country on Tuesday and messages on social media encouraged people to withdraw cash despite not having funds in their accounts.
An Garda Siochana said it was aware of an “unusual volume of activity” at some ATMs across the country.
In a statement on Wednesday, the bank said: “Yesterday a technical issue impacted a number of Bank of Ireland’s services.
“Our teams restored these services overnight and all services are available to customers this morning. Overnight payments to accounts may appear throughout the day.
“We are aware that the technical issue meant some customers were able to withdraw or transfer funds above their normal limits.
“These transfers and withdrawals will be applied to customers’ accounts today. We urge any customer who may find themselves in financial difficulty due to overdrawing on their account to contact us.
“We sincerely apologise for the disruption this outage caused – we know we fell far below the standards our customers expect from us.”