The world’s largest company could owe more than $8 billion in back taxes, a European Commission investigation has revealed. The investigation into Apple Inc’s tax policies has been going on since 2014, and a report on it could come out by March this year.

The company is among a list of others, including Starbucks Corp., Amazon Corp., and McDonalds Corp., that are being investigated for its tax policies. Apple Inc has been accused of using subsidiaries in Ireland to avoid paying taxes on money earned outside the United States, Bloomberg reported. Apple generates around 55% of its revenue outside the US, and pays 1.8% in foreign tax rates. If the Commission enforces a new tax standard, Apple may owe 12.5% in taxes, on $64.1 billion generated between 2004 and 2012, Bloomberg Intelligence said.

The company has said it will appeal any adverse ruling and denied that it is using tricks to avoid paying taxes. Apple calculates its taxes using low operating costs, a move that decreases a huge amount from what it would have to pay to Ireland’s government.