When different countries consider themselves competent to tax the same profits of a company, a cross-border economic activity is disadvantaged. Therefore, bilateral treaties are concluded in which States allocate taxing powers between them. Nevertheless, the risk remains that a treaty can be interpreted in different ways by two countries so that both of them can decide to tax or not to tax, causing a disproportionate outcome. The company can in that case opt to initiate internal proceedings to enforce compliance with the treaty in each State concerned. This option also involves the risk that national courts in both States would reach a contradictory decision. Therefore, the mutual agreement procedure was introduced, in which States consult each other to jointly resolve the dispute. If an agreement cannot be reached, a possibility for a binding arbitration procedure will be provided. Nevertheless, the rights and/or obligations of a taxpayer in these procedures remain unclear. After initiating the proceedings, the involvement of the taxpayer is rather limited. This is deplored in the legal doctrine, however, without fundamentally defining the legal position of the taxpayer under these procedures. A clear description of this legal position should allow to indicate on a more solid basis which rights and/or obligations can or cannot be derived from that position, and consequently, which rights he should or should not be able to invoke.