The Meaning of the Principal Purpose Test: One Ring to Bind Them All?

Due to the introduction of the Multilateral Convention (MLI), an ever-growing number of the world’s international tax treaties will contain a treaty-based anti-avoidance rule known as the principal purpose test (PPT). These PPT provisions will almost certainly play an extremely important role in preventing international tax avoidance. With the introduction of such broad and powerful anti-avoidance rules comes the risk of individual countries, through their revenue authorities and their courts, developing divergent and state-centric views as to the interpretation of the PPT. This risk is quite considerable, and there are many reasons why a harmonized basis of interpretation may not, in reality, emerge. If courts pursue an individual and diverse approach to the interpretation of the PPT, the same transaction will be viewed as being effective in one jurisdiction and ineffective in another. From a broader perspective, this is undesirable, and it should not occur for policy and interpretative reasons. Why is the case for interpreting the PPT consistently, with a common meaning, so compelling? There is one major reason, and it is an obvious one: the PPT can now be found in thousands of treaties, and it is exactly the same test in all of these. It is clear that an international autonomous meaning is intended to be introduced through the uniform adoption of the PPT. A universal interpretation may be possible if courts and revenue authorities apply a consistent approach to interpretation. The approach, detailed in this article, suggests that international tax treaties should be interpreted in accordance with (i) the ordinary meaning of the text of the PPT; (ii) due consideration of the context and the MLI’s object and purpose; and (iii) consideration of how the MLI, as a successive treaty, relates to the covered tax agreement (CTA) that it amends. This article analyses the PPT rule from a normative position and sets out an appropriate basis for the approach to interpreting the PPT. Using all available sources and reports, including examples of the application of the test, this article provides a comprehensive framework for interpreting the PPT and answers the following questions, amongst others: (i) How is the PPT designed to override other provisions in the CTA (including other general anti-avoidance rules)? (ii) Is the substantive test based on an objective assessment of the arrangement or transaction or on the subjective position/mind of the taxpayer? (iii) Does the proviso place an onus of proof upon the taxpayer?