Apple has been accused of sheltering profits through its Irish base for years, culminating in a three-year probe to decide whether this was illegal, and now looks set to be hit with a large fine.
However, other outlets are disputing that number, claiming it could only run to the hundreds of millions, and one minister claiming it could be as low as €100 million (around £85m / $110m / AU$147m).
Apple has previously been accused by a Senate committee of using Ireland to avoid paying tax on its US income, something the company has denied.
Who's done what?
The issue here is not whether Apple's practices in Ireland have been illegal, but whether Ireland has offered specific companies favourable tax deals, which would be considered 'state aid' and is unlawful.
All sources quoted in this case are clear that Apple and the Irish Government will appeal the ruling, believing that the arrangement between the companies is lawful and adheres to the correct tax laws.
"Ireland is confident that there is no breach of state aid rules in this case and has already issued a formal response to the commission earlier this month," the department of finance in Dublin told the Guardian in 2015.
What this means for the consumer is unclear, but if the worst case scenario happens and Apple is forced to pay €19 billion (around £16bn / $21bn / AU$28bn), the largest number predicted by analysts), this could impact the cost of iPhones, iPads and other services as the brand looks to make up the profit margins elsewhere.
However, even if a ruling does appear today requiring a large fine from the EU, that will only be a recommendation as the Irish authorities will be tasked with calculating the exact number.
The appeals process will also drag the whole process out, so the final figure Apple could be hit with is a long way from set.
- This story will be updated as more information becomes available.