see
http://europa.eu/rapid/press-release_IP-16-2923_en.htm
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.
Therefore, only a small percentage of Apple Sales International's profits were taxed in Ireland, and the rest was taxed nowhere. In 2011, for example (according to figures released at US Senate public hearings), Apple Sales International recorded profits of US$ 22 billion (c.a. €16 billion
[1]) but under the terms of the tax ruling only around €50 million were considered taxable in Ireland, leaving €15.95 billion of profits untaxed. As a result, Apple Sales International paid less than €10 million of corporate tax in Ireland in 2011 – an effective tax rate of about 0.05% on its overall annual profits. In subsequent years, Apple Sales International's recorded profits continued to increase but the profits considered taxable in Ireland under the terms of the tax ruling did not. Thus this effective tax rate decreased further to only 0.005% in 2014.