European competition commissioner Margrethe Vestager has revealed that Apple's €13 billion tax bill can be reduced if its Irish subsidiaries make payments to its US parent.

According to the Irish Independent, Vestager commented this morning:

"The amount to be paid back to Ireland would also be reduced if the two companies were required to pay larger amounts of money to their US parent company to fund the research and development efforts, in addition to the annual payments they have made."

She was speaking as the European Commission's full ruling on Apple's Irish tax status was published.

The company has two companies established here, Apple Sales International and Apple Operations Europe, with the former accounting for most of the unpaid taxes.

Vestager went on to say that other countries, "in the EU or elsewhere", can look at the investigation and if they conclude that Apple should have recorded its sales in those countries instead of Ireland, they could require Apple to pay more tax locally. That would reduce the amount to be paid back to Ireland.

Vestager stated that Ireland had "artificially reduced" Apple's tax payments over a 20-year period and that two tax rulings had been made specifically to help Apple.

She said:

"This decision sends a clear message: Member States cannot give unfair tax benefits to selected companies. No matter if they are European or foreign, large or small, part of a group or not."