The comprehensive two-part article deals with the Organisation for Economic Co-operation and Development (OECD) Commentaries’ relevance in tax treaty interpretation, particularly from the perspective of Articles 31 and 32 of the 1969 Vienna Convention on the Law of Treaties. The purpose of the article is to establish the legal basis for the use of the OECD Commentaries in the interpretative process and, most importantly, to determine their relative weight in the interpretative undertaking.
The main finding is that the relative value of the OECD Commentaries is not fixed but varies from case to case. The Commentaries’ interpretative weight in each particular situation depends on whether it can be established that the common intention of the tax treaty parties was to copy the substance of the OECD MC in the relevant terms of their bilateral treaty. Accordingly, the Commentaries have a dual role to play. They may be ‘a commentary’ or ‘the Commentary’.
When assessing which version of the OECD Commentaries is the one that corresponds to the intended substance of the tax treaty, it is noteworthy that also the temporal element of treaty interpretation (static or dynamic) must be decided case-by-case. It may be that the common intention of the parties was to give the treaty terms a fixed meaning but they may as well have wanted their mutual treaty, or parts of it, to function as a ‘living instrument’.Intertax