Irish Nationwide Building Society was the only financial institution unable to fulfil its commitment to exchange pounds for euro for non-customers yesterday. The society said this was due to the high level of business.
In a statement, the society said it would convert cash free of charge where possible for customers and non-customers alike.
"Due to the unprecedented number of people entering our branches to convert cash, combined with the logistical and security issues involved in restocking our branches we have had to prioritise and meet our existing customers' requirements first," the statement said.
All banks, building societies and An Post have signed up to offer this free service to assist with the changeover to the euro until Irish notes and coins cease to be legal tender on February 9th.
Financial institutions across the State reported huge numbers of transactions throughout the day as people sought euro notes and coins.
A spokeswoman for An Post said all of its offices were exceptionally busy, with the payment of child benefits adding to the numbers using its services.
A number of people queued to have their savings books updated to the euro amount. The spokeswoman said this was unnecessary as all balances were automatically converted to euro.
It was the same story at all financial institutions, with the banks reporting long queues. AIB reported a huge level of public interest, with the biggest number of customer transactions in Dublin, Cork and Limerick.
By 3 p.m. some 300,000 electronic transactions including Laser and credit card and ATMs had been processed. Some 90 per cent of all retailers who use AIB point-of-sale machines reported that the system was working normally, the bank said.
Business volumes were significantly higher than on the same day last year, with the number of people exchanging relatively small amounts of cash much higher than expected.
All ATM machines across the Republic are now back in service and dispensing euro.
A spokeswoman for Bank of Ireland said there were long queues during the day at most branches but there was a full complement of staff to deal with customers.
It reported 156,000 cash transactions at its cash machines yesterday, with the average withdrawal amounting to €102, which was well above demand levels in the same period last year.