Discusses the jurisdiction or right to tax international commercial transactions, including identification of relevant connecting factors, which may be based on the person deriving the income or activities producing the income. In the context of persons, the discussion considers the characterisation of persons under domestic law and its interaction with entity characterisation under tax treaties. It moves to consider residence as a connecting factor, both under domestic law and tax treaties and tax treaty tiebreakers applicable to dual residents. Residence is fundamental to the application of tax treaties. The discussion briefly considers the location of activities that found a jurisdiction to tax based on source of income. These matters are compared to the scope of the fundamental freedoms and relevant Directives under EU Law. The discussion then considers divided economic allegiance and particularly where source and residence are divided between countries. Various notions of neutrality and efficiency are discussed, as well as rules preventing cross-border restrictions, including nondiscrimination. Focus moves to the internation relationship including the OECD harmful tax competition project and BEPS project. These are compared with EU state aid rules and the EU code of conduct on harmful tax practices. Methods of allocating tax rights are discussed.