The so-called indirect tax harmonization process, undertaken by the European Court of Justice, and partly fueled by the European Commission, is giving place to a radical transformation of non-resident taxation. The traditional principle derived from international taxation, namely, that residents and non-residents deserve a different treatment as they are not in the same position, is increasingly being challenged by the Court and the Commission. The reasoning logic of the Court is not always easy to follow. However, it is slowly becoming clear that, as a consequence of the interaction and common influence of European tax law and International tax law, a “Statute of the EU-based non-resident” is being created. This means, growingly, that non-residents in a given Member State, that are resident in another, have a distinct regime that profoundly shapes their tax liability. This paper intends to assess the functioning of the said regime, in order to help shed some light in what is increasingly becoming a “tax jungle”, where Member States reform their Tax Codes in order to align them with the latest ECJ resolution, while the little coherence left creates ever new loopholes that have then to be closed, such increasing the complexity of the tax systems. Finally, the article pays particular attention to the Spanish tax on non-residents (Impuesto sobre la renta de no residentes) in order to show the perverse effects of the indirect harmonization of the tax law.