The article discusses the legal aspects of supranational legal regulation of value added taxation in the Persian Gulf countries. The novelty of the research lies in the comparative aspect of the legal study of supranational law on the value-added tax in the Gulf countries, which allows formulating fundamentally new characteristics and interpretations that extend the theoretical and legal views on the legal mechanism of VAT, and analyzing the key provisions of the legal regulation of VAT of the states that are parties to the Common VAT Agreement. The issues of the Agreement for the countries of the Gulf Cooperation Council, as well as acts of national legislation on this tax, were studied. The analysis of the provisions of the Agreement allows concluding that the tax instrument this Agreement regulates can be classified as a type of neutral legal regulation of value-added taxation. Its peculiarity is that the country for one reason or another introduces VAT into the national tax system with minimal tax rates and continues to keep it at a low level that does not have a restraining effect on the development of its own industry. This is the reference point for the Common VAT Agreement for the countries of the Gulf Cooperation Council. The research shows that the supranational legislation of the Persian Gulf countries covers the most complex and fundamentally significant issues of legal regulation of value-added taxation, which developed taking into account the accumulated world experience in the administration of this tax. Conclusions have been obtained that the main direction of the adopted supranational legislation is the creation of a unified legal framework for the development of a coordinated legal regulation of VAT in each of the six Arab states of the Persian Gulf. The definitions of concepts that are crucial for VAT regulation are given, among which the following can be distinguished: reverse VAT accrual, input tax, deductible tax, net tax, mandatory registration threshold, voluntary registration threshold, and tax group. In the final part of the work, it is concluded that the second regional system of legal regulation of value-added taxation after the European one is being created, which begins its development on the basis of supranational legislation. Within its framework, the states that are parties to the Agreement shall organize administrative cooperation in the following areas: (1) exchange of information necessary for determining tax accuracy; (2) coordination of synchronized audit procedures and participation in audits; (3) assistance in tax collection and adoption of necessary procedures related to VAT collection.