The Government's appeal of the Apple tax ruling will be lodged in the European Courts today.
In August, the European Commission ruled that Apple should pay €13bn in back taxes to Ireland.
The Government here says the money is not in fact owed to Ireland and will appeal on that basis.
The deadline to lodge an appeal is tomorrow, Thursday.
The United States has indicated it might seek some of the €13bn after the European Commission said other countries might be able to stake a claim to the money, if it can prove the tax should have been paid there instead.
Finance Minister Michael Noonan said the comment shows that Ireland was never supposed to levy the tax on Apple in the first place.