Double Taxation, Finland and the Single Market

The recent decision of the Finnish Supreme Administrative Court on the taxation of dividends paid to foreign pension funds has reignited debate about the compatibility of domestic dividend withholding tax regimes with European Union law. The decision — and the broader question it raises about the treatment of comparable situations involving resident and non-resident entities — goes to the heart of the tension between national tax sovereignty and the requirements of the internal market.

At stake is a deceptively simple question: when a member state exempts domestic pension funds from dividend withholding tax but subjects foreign pension funds to such tax, is that differential treatment compatible with the free movement of capital? The answer, as the Court of Justice of the European Union has made clear on numerous occasions, is that it is not — at least where the domestic and foreign funds are in objectively comparable situations.

The Finnish case is a reminder that the principle of non-discrimination in EU tax law is not a static concept. It evolves with the case law of the Court of Justice, which continues to refine the conditions under which domestic and cross-border situations may be treated differently, and the circumstances in which such differential treatment constitutes a prohibited restriction.

For tax practitioners, this evolution presents both challenges and opportunities. The challenge lies in advising clients on the risks and uncertainties of cross-border investments in a legal environment that is in constant flux. The opportunity lies in the identification of situations where domestic tax rules unjustifiably discriminate against non-residents — and in the pursuit of the remedies that EU law provides.

The Finnish case also highlights the importance of procedural rights in the context of EU tax law. The right to an effective remedy, enshrined in Article 47 of the Charter of Fundamental Rights of the European Union, is not satisfied by the mere formal availability of judicial review. It requires that the review be effective in practice — that it be capable of providing timely and adequate redress for the taxpayer who has suffered unjustified discrimination.

This is a lesson that tax administrations across the European Union would do well to take to heart. The internal market is not built on formal equality alone; it requires substantive equality — equality that is enforceable in practice, not merely proclaimed in principle.

The Finnish case is a small but instructive example of the ongoing process by which European integration continues to reshape national tax systems. It is a process that is far from complete — and one that will continue to generate controversy and litigation for years to come.

The single market is, in the end, a project of trust. It asks member states to accept constraints on their sovereignty in exchange for the benefits of economic integration. When those constraints are respected — when member states honour their obligations under EU law — the project works. When they are not, the result is not merely a legal dispute but a failure of solidarity.

Finland's experience is a reminder that solidarity in the internal market is not only an economic concept. It is also a legal one.

And that, perhaps, is the most important lesson of all.

The principle of non-discrimination in EU tax law is, in the end, a principle of solidarity — a commitment to treating all participants in the internal market with equal dignity and respect.