Bank of Ireland (BoI) was hit by another outage on Friday when its mobile banking app went down for around four hours.
From around noon on Friday, customers were unable to log on to any of the bank's apps or websites.
Furthermore, customers were unable to complete any online transactions involving BoI credit cards because the verification process was not working.
In a statement issued on Friday afternoon, the bank put the issue down to an unspecified "technical issue".
"There was a technical issue this afternoon which required us to take it offline while we fixed the problem,” read the statement. "We are very sorry for the inconvenience caused to our customers today.”
The bank has been hit by a number of technical issues in recent years. Last August, a "singificant technology outage" led to long queues at BoI ATMs after a rumour circulated that customers could withdraw money without their accounts being debited.
The rumour proved to be untrue but it did lead the country's finance minister Michael McGrath to rebuke the bank for "too many such instances in recent years".
BoI was also fined €24.5m in 2021 for deficiencies in its IT systems.