On May 6th, AIB apologised for overcharging certain foreign exchange customers over an eight-year period but insisted senior management only learned of the overcharging in recent times. The bank has so far estimated its liability at €20 million, plus €5 million in interest.

On May 2th, the bank admitted about 570 mortgage customers were automatically given payment protection without their approval. The bank said it would contact the customers and ask them whether they wanted a refund. Asked whether there would be a sizeable liability, the bank described it as a "small issue".

On May 24th, the bank admitted it had repaid €3.4 million to some customers who were incorrectly charged on trusts they held with the bank. AIB said it also expected to pay up to €2 million to others who are entitled to refunds. The bank said that, in 2002, it identified a potential issue in relation to the charges applied to trusts that had been established before AIB was formed.

Before the latest spate of problems, AIB has been embroiled in more public controversies than arguably any other Irish bank.

In 2002, the bank was rocked by the Allfirst scandal, when it emerged that John Rusnak, a trader at the AIB US subsidiary, was responsible for losses of $691 million (€580 million). The affair grabbed headlines around the world, drawing comparisons with the demise of Barings Bank at the hands of "rogue trader" Nick Leeson.

In 1985, AIB was forced to seek government assistance when Insurance Corporation of Ireland, a wholly owned division, racked up liabilities estimated at up to £120 million (€150 million), threatening its very survival. Although it had reaped profits of around £80 million in the previous year, AIB warned it might not be able to withstand such a hit.

In 1999, AIB was embroiled in the DIRT tax evasion affair. The affair broke when it was revealed that AIB had thousands of "bogus non-resident accounts" set up by Irish citizens to avoid DIRT.

The Dáil Public Accounts Committee (PAC) launched an investigation. This culminated in an investigation by a sub-committee of the PAC which uncovered evasion through non-resident accounts across the financial system.AIB made a £90 million (€114 million) settlement with the Revenue following a hearing. The payment was the largest tax settlement since the State's foundation.