> The two tax rulings issued by Ireland concerned the internal allocation of these profits within Apple Sales International (rather than the wider set-up of Apple's sales operations in Europe). Specifically, they endorsed a split of the profits for tax purposes in Ireland: Under the agreed method, most profits were internally allocated away from Ireland to a "head office" within Apple Sales International. This "head office" was not based in any country and did not have any employees or own premises. Its activities consisted solely of occasional board meetings. Only a fraction of the profits of Apple Sales International were allocated to its Irish branch and subject to tax in Ireland. The remaining vast majority of profits were allocated to the "head office", where they remained untaxed. ...
Inforgraphic from same link, notice the text to the left in the red box.
http://ec.europa.eu/competition/publications/infographics/20...
is the link to the EU press release that answers your question. Irish govt. tax deal is in violation of EU tax law and the EU recommend that the Irish govt. seek recompense to the tune of €13bn plus interest.