Bank of Ireland estimated its total tax bill at £2.8 million including interest and penalties; but the bank has agreed a settlement of £30.5 million on foot of a Revenue audit.

AIB estimates the most it owes is £35 million - including interest and penalties - although contested internal audit reports suggest its liability is closer to £100 million; it is awaiting a tax demand from the Revenue.

ACC Bank's DIRT liabilities are estimated to be between £1.5 million and £17.5 million before penalties and interest. It too is awaiting an assessment by the Revenue.

National Irish Bank has made a provision of £1 million for any potential liability.