Most states within the EU have some kind of CFC-legislation that allows the state in question to tax its residents for gains accrued within foreign companies that they control. CFC-legislations are usually said to counteract tax avoidance and they generally target only income of companies in low tax regimes. Such tax regimes are however not only found in pure tax havens. Some of the member states of the EU have set up preferential tax regimes, often limited to foreign financial offshore activities. Can it be a restriction of the freedom of establishment in article 43 EC to tax a resident taxpayer on CFC-basis for the income of a company resident in another member state? In the affirmative, can such a restriction be justified and if so, on which ground? Can it perhaps be easier to argue in favour of CFC-rules after the recent judgment of Marks and Spencer where the ECJ seems to have applied a broader ground of justification in respect of the counteraction of tax avoidance?

These are some of the main questions dealt with in this thesis.