Most Favoured Nation Clauses in Tax Treaties: Comparative Analysis and Main Issues

Over time, the use of most favoured nation clauses has seen widespread adoption in double tax treaties, especially in those agreed with developing countries. The use of such clauses, however, does not appear to have been supported frequently by tax policies and/or careful ad hoc analysis, e.g. on the structure, wording and consequences of these provisions in the relevant tax treaty networks. The lack of a model clause in the OECD and UN Model Conventions, and the proliferation of many variants could have played a role in this regard. Because of this, the application of this clause still today triggers many issues that can prevent, for example, its clear and correct interpretation and application and the enjoyment of legitimate treaty benefits by taxpayers or may entail challenges for treaty negotiations. These issues may relate mainly to the nature of such clauses and the policies behind them, as well as to the lack of a clear wording that can facilitate their application in different ways. In light of the above, the purpose of this article is to outline certain critical situations that could occur when applying such clauses. The analysis was conducted after assessing the historical background of most favoured nation clauses and carrying out a comparative analysis through the different variants used in the Chilean, Indian and Italian tax treaty network to assess if different approaches have been adopted so far by countries with different economic, legal and tax backgrounds.