Ireland will begin collecting €13 billion ($15.46 billion) in back taxes from Apple by early next year after both sides agreed to the terms of an escrow fund for the money.

"We have now reached agreement with Apple in relation to the principles and operation of the escrow fund," Ireland;s Finance Minister Paschal Donohoe said on Monday.

The European Union in 2016 ordered Dublin to retrieve the billions of euros from Apple in uncollected taxes, which the EU said Apple avoided paying with the help of favorable tax deals from Ireland.

The European Commission said the record sum was the result of Apple receiving unfair tax incentives from Ireland. EU said the previous tax deal with Ireland had allowed Apple to pay almost zero tax on European profits between 2003 and 2014

Both Dublin and Apple have challenged the EU order.