The Principal Purpose Test (PPT) is the primary anti-treaty-abuse standard introduced by the OECD's Multilateral Instrument, signed in June 2017 and in force from 1 July 2018, and it now applies to a growing number of bilateral tax treaties that have been modified through the MLI. Under the PPT, a treaty benefit may be denied if one of the principal purposes of an arrangement or transaction was to obtain that benefit, unless granting it would be in accordance with the object and purpose of the relevant treaty provision. For cross-border investors and multinational groups, this creates a significant and ongoing tax risk management challenge that demands careful, substance-based tax structuring before, not after, a transaction is entered into.
The Legal Framework: From BEPS Action 6 to the MLI
The PPT has its roots in BEPS Action 6, which identified the prevention of treaty abuse as one of the minimum standards that all OECD and G20 jurisdictions committed to implementing. The MLI was the primary legal vehicle chosen to transpose this standard into the existing network of bilateral tax treaties without requiring bilateral renegotiation of each individual agreement. When two treaty partners have both listed a bilateral convention as a Covered Tax Agreement (CTA) and have opted – or defaulted – into Article 7 of the MLI, that convention becomes subject to the PPT from the date the MLI enters into force for both states.
Article 7(1) of the MLI sets out the core rule: a benefit shall not be granted if it is reasonable to conclude that obtaining the benefit was one of the principal purposes of an arrangement or transaction. The standard deliberately uses the phrase one of the principal purposes, not the sole or dominant purpose. This is a meaningful distinction: even where a genuine commercial rationale exists, the presence of a tax-driven purpose alongside it may be sufficient to trigger denial. The burden of this analysis falls primarily on the taxpayer seeking the benefit, though in practice tax authorities bear the procedural burden of raising a challenge during a tax audit.
Jurisdictions that preferred a more certain, rule-based approach could instead elect the Limitation on Benefits (LOB) provision, either alone or in combination with the PPT. However, the PPT without the LOB has emerged as the more widely adopted option, precisely because it is a subjective, facts-and-circumstances test that tax administrations consider more flexible and broadly applicable.
Interpretation and Open Questions
The PPT's relative brevity in the treaty text belies a considerable degree of interpretive uncertainty. Several questions remain genuinely unresolved in international tax law and have begun to surface in litigation and administrative guidance across jurisdictions.
- What constitutes a "principal" purpose? The OECD Commentary suggests that a purpose is principal if it is not merely incidental. Courts and tax authorities have taken differing views on whether this means the purpose must rank alongside other primary business objectives, or whether any significant tax motivation suffices.
- Who bears the evidential weight? The MLI text does not allocate the burden of proof expressly. Some jurisdictions treat the initial presumption as one for the tax authority to rebut, while others place an affirmative obligation on the taxpayer to demonstrate that tax was not a principal purpose.
- The saving clause interaction: Where a CTA contains a saving clause preserving a state's right to tax its own residents, the PPT's interaction with that clause can produce asymmetric results that were not always anticipated by the parties at treaty conclusion.
- Retroactive effect on existing structures: Structures that were lawful and tax-efficient under a pre-MLI bilateral treaty may no longer be so once the MLI modifies that treaty. The question of whether legitimate expectations or transitional protections are available is answered differently under domestic law in different jurisdictions.
- Relationship with domestic general anti-avoidance rules (GAARs): In many states, the PPT operates as a treaty-level rule that sits alongside, and does not replace, national anti-avoidance rules. A structure that survives the PPT analysis may still be challenged under a domestic GAAR, or vice versa.
These open questions mean that the PPT does not offer a bright-line test that taxpayers can apply with confidence in isolation. Legal advice calibrated to the specific treaty relationship and the jurisdictions involved is essential for sound tax risk management.
Practical Impact: How the PPT Changes Tax Audit Risk
From a practical standpoint, the PPT has shifted the risk profile of cross-border tax structuring in ways that are already visible in the behaviour of tax authorities. Competent authorities are scrutinising holding company arrangements, dividend routing, interest and royalty flows, and treaty-based permanent establishment planning with greater intensity than before the MLI came into force.
In a tax audit context, investigators typically examine contemporaneous documentation, internal communications, board minutes, and the economic substance at each intermediate entity. The absence of documented, non-tax business reasons for a particular structure or jurisdiction choice has become a material audit risk factor. Where such documentation does not exist or is inconsistent, the practical leverage of the PPT is substantial: the tax authority can assert that one of the principal purposes of the arrangement was to access treaty benefits and shift the dialogue to one of refutation rather than initial justification.
For groups operating through intermediate jurisdictions in Asia-Pacific, for example, the interaction of the PPT with treaty networks can be particularly complex. The specific treaty relationships, the MLI positions taken by each state, and any domestic implementation rules all affect the ultimate exposure. Clients with Japanese operations or investment structures touching Japan can find detailed analysis of those considerations on our Japan tax structuring service page.
Transfer pricing is closely connected to this analysis. A structure that has been challenged under the PPT will often also attract transfer pricing scrutiny, because the denial of treaty benefits may trigger questions about arm's length pricing of intercompany transactions that relied on the favourable treaty rate. Treating PPT risk and transfer pricing risk as independent silos is, therefore, a common and costly mistake.
If your group's current treaty arrangements have not been reviewed in light of the MLI's modifications to your Covered Tax Agreements, this is an appropriate moment to commission that analysis. Please contact our team at info@ferrazwhitmore.com or visit our contacts page to discuss your situation.
Cross-Border Implications: The Asymmetry Problem
One underappreciated dimension of the PPT is the asymmetry it introduces into cross-border structures involving more than two jurisdictions. In a triangular arrangement – for example, a parent in jurisdiction A, an intermediate holding company in jurisdiction B, and an operating subsidiary in jurisdiction C – the PPT may be applied by the competent authorities of both B and C, applying their own interpretive frameworks and drawing on different domestic court decisions and administrative guidance.
The OECD has published Commentary and examples to guide consistent interpretation, but that Commentary is not legally binding in most jurisdictions and does not override domestic law or treaty text. Where states disagree on whether the PPT applies to a particular arrangement, the taxpayer may face double taxation without a clear mutual agreement procedure (MAP) remedy. MAP under the relevant CTA may provide some relief, but MAP proceedings are time-consuming, outcome-uncertain, and not available as a matter of right in all scenarios.
The asymmetry problem is compounded when one of the states involved has adopted additional domestic anti-avoidance rules that mirror, but are not identical to, the PPT. In those cases, the standard for denial of benefits at the domestic level may diverge from the treaty standard, and litigation risk multiplies accordingly.
For investors whose corporate structures span multiple jurisdictions and involve holding entities whose primary function is to access favourable treaty networks, a comprehensive review under the combined lens of anti-avoidance rules across each relevant jurisdiction is the prudent course. Our comparative analysis of beneficial ownership case law offers useful context for understanding how courts in different systems have approached overlapping anti-abuse doctrines.
Strategic Recommendations for Businesses and Investors
There is no single strategy that eliminates PPT exposure across all fact patterns. What follows is a framework of measures that, taken together, significantly reduce the probability of a successful PPT challenge and support an effective defence if one arises.
- Substance before structure: Intermediate entities should have genuine economic substance in the jurisdiction through which they operate – real decision-making, employees with relevant expertise, adequate capitalisation, and operational functions that go beyond holding shares or channelling payments.
- Contemporaneous documentation: The business rationale for each structural choice should be documented at the time the decision is made, not reconstructed during a tax audit. Board resolutions, investment committee papers, and commercial analysis memos are more persuasive than post hoc explanations.
- Treaty mapping: For each bilateral relationship in a group structure, verify whether the treaty has been modified by the MLI, which MLI provisions apply, and whether the state concerned has adopted any domestic implementation rules that supplement or modify the treaty-level PPT.
- Stress-testing with a purpose analysis: For each key structure, conduct an honest internal assessment of the purposes pursued. If tax reduction is objectively among the top-tier purposes, consider whether the structure can be redesigned so that business reasons are genuinely, and demonstrably, primary.
- Integrated transfer pricing and treaty analysis: Ensure that transfer pricing policies for entities relying on treaty benefits are reviewed in conjunction with the PPT analysis, so that an adverse treaty outcome does not create cascading transfer pricing exposure.
- Horizon monitoring: The MLI's reach continues to expand as states complete ratification and as more treaties qualify as CTAs. A structure that is not currently affected may become subject to the PPT when an additional state completes its MLI ratification process.
Where restructuring is necessary or advisable, the corporate law dimension requires careful attention alongside the tax analysis. Mergers, conversions, or redomiciliations carried out primarily to address treaty abuse concerns may themselves attract PPT scrutiny if they lack independent commercial justification. Our corporate law practice works alongside our tax team to ensure that structural changes are designed and implemented on a legally coherent basis.
Outlook: Where the PPT Is Heading
The PPT is not a static standard. As more jurisdictions implement and litigate it, a body of administrative decisions and case law is accumulating that will increasingly define its contours. The OECD's ongoing work under the Inclusive Framework, the publication of further Commentary, and developing domestic jurisprudence in major jurisdictions are all likely to refine – and in some areas narrow – the interpretive uncertainty that currently surrounds the test.
At the same time, political pressure for effective taxation of cross-border structures remains high, and tax administrations in major economies have invested in specialist anti-avoidance units with the capacity to pursue complex PPT challenges. The probability of a PPT audit challenge for a group with significant cross-border treaty-dependent income, but without robust substance and documentation, has increased materially since the MLI came into force in July 2018 – and is not likely to diminish in the near term.
For investors and businesses that have not yet reviewed the impact of the MLI on their existing structures, or that are planning new cross-border arrangements, the analytical and procedural steps outlined in this article represent a sound starting point. The cost of proactive review is almost invariably less than the cost of defending a challenge.
Ferraz & Whitmore advises on international tax risk management, treaty structuring, and cross-border transactions across multiple jurisdictions. To discuss how the PPT applies to your current or planned arrangements, please reach out to our team at info@ferrazwhitmore.com or visit our contacts page.
Disclaimer: This publication is provided for informational purposes only and does not constitute legal advice. The information herein should not be relied upon as a substitute for professional legal counsel tailored to your specific circumstances. Ferraz & Whitmore assumes no liability for actions taken or not taken based on the contents of this material. For advice regarding your particular situation, please contact info@ferrazwhitmore.com.