The author first considers the consequences of the coexistence of national tax systems, including the existence of disparities between jurisdictions, the fact that the Member States may treat situations that arise fully within their own jurisdiction differently from those that are partly within and partly without their jurisdiction, and international juridical double taxation. The author then analyses to what extent the Community principles of non-discrimination and non-hindrance prohibit the impediments resulting from the facts that different rules apply in different jurisdictions, that the rules in a single jurisdiction treat internal and cross-border situations differently, and that tax jurisdictions tend to overlap. Finally, the author argues against the concept of "dislocations".