OECD Pillar One: How Profit Reallocation Will Work

OECD Pillar One reallocates taxing rights over the largest multinationals to market jurisdictions. Here is what it means and who it affects.

OECD Pillar One is the most ambitious attempt in a century to rewrite where the world's largest companies pay tax. For more than a hundred years, the international system has rested on a simple premise: a business pays corporate tax where it has a physical presence. The digital economy broke that premise. A company can now serve millions of customers in a country without an office, a factory, or a single local employee.

OECD Pillar One is the response. It reallocates a slice of the profits of the very largest and most profitable multinationals to the jurisdictions where their customers and users actually sit, regardless of physical presence. For most private clients and mid-market businesses, the direct impact is limited. For the groups in scope, and for the wider treaty environment everyone operates within, the implications are significant.

This guide explains what Pillar One is, how the mechanics are intended to work, where the project stands as at 2026, and why it matters even to those who fall well below the thresholds.

What problem Pillar One is trying to solve

The starting point is "nexus" and "profit allocation". Traditional rules say a country can only tax a foreign business if that business has a taxable presence there, typically a permanent establishment. Highly digitalised firms argued, correctly under the old rules, that selling remotely created no such presence.

Market countries grew frustrated. Several responded with unilateral digital services taxes, turnover-based levies on local digital revenue. These were unpopular with the United States in particular, threatened trade retaliation, and risked a patchwork of overlapping charges. Pillar One was conceived, under the OECD and G20 Inclusive Framework, as the multilateral alternative: a single, coordinated reallocation that would replace the unilateral measures.

The political bargain is straightforward to state. Market jurisdictions get a defined right to tax part of the profit earned from their consumers. In exchange, they agree to withdraw and refrain from digital services taxes. The technical execution, as ever, is where the difficulty lies.

The two building blocks: Amount A and Amount B

Pillar One is usually described in two parts.

Amount A is the headline reform. It applies to the largest and most profitable multinational groups, those above very high global revenue and profitability thresholds. For groups in scope, a portion of their "residual" profit, broadly the profit above a routine return, is reallocated to market jurisdictions according to where revenue is sourced. A country qualifies to tax a share only once a group's revenue sourced there crosses a defined nexus threshold.

The effect is that a small number of the world's biggest groups would file and pay under a new, partly formulaic allocation layered on top of the existing system. Mechanisms to relieve the resulting double taxation, by relieving profit in the jurisdictions that previously held it, are central to the design and among the hardest features to finalise.

Amount B is narrower and broader at the same time. It simplifies and standardises the transfer-pricing return on routine "baseline" marketing and distribution activities. Rather than every local distributor negotiating its arm's-length margin from scratch, Amount B provides a more mechanical, predictable return. This is intended to reduce disputes and compliance cost, and it potentially touches far more businesses than Amount A, because routine distribution is everywhere.

Where the project stands as at 2026

It is important to be candid about status. Pillar One has been politically agreed in principle by a large group of Inclusive Framework members, but it depends on a Multilateral Convention that must be signed and then ratified domestically before Amount A can take legal effect. Ratification, particularly in the United States, has been the persistent obstacle, because the reallocation of taxing rights over major American groups is contentious at home.

Amount B has advanced on a somewhat different track and has been built into the OECD transfer-pricing guidance, with jurisdictions able to adopt it, though application is uneven.

The practical takeaways as at 2026: timelines have repeatedly moved, the standstill on new digital services taxes is conditional and fragile, and the precise scope and rates remain subject to the final instruments. We treat any specific figure or date as provisional and confirm the current position before clients rely on it.

Who is actually in scope

Most of our clients are not directly caught by Amount A. The revenue and profitability thresholds are deliberately set so high that only a limited number of the very largest groups qualify, and regulated financial services and extractive industries are generally excluded from Amount A.

The businesses that should be paying close attention are large, highly profitable groups with substantial cross-border consumer or user revenue, especially those with a digital or platform element. For those groups, the work is not only modelling the tax cost but rebuilding data systems to source revenue by market jurisdiction, a non-trivial exercise.

Amount B reaches further down. Any group with local marketing and distribution subsidiaries should understand how a standardised baseline return might change its transfer-pricing position, in either direction.

Why it matters even below the thresholds

Three reasons. First, the treaty environment is shifting. Pillar One sits alongside Pillar Two, the global minimum tax, and together they signal a durable move away from tax competition based purely on headline rates and towards taxation aligned with real activity and real markets. Structures built on the old assumptions deserve review.

Second, the digital services tax question is unresolved. If multilateral implementation stalls, unilateral measures may return or persist. Businesses selling digitally into multiple markets could face turnover-based charges that bite regardless of profitability, which is a very different risk profile from a profits tax.

Third, substance and sourcing data are now strategic. The direction of travel rewards groups that can clearly evidence where value is created and where revenue arises. Clean, defensible data is becoming a compliance asset in its own right.

Common misconceptions

We frequently correct three. Pillar One is not a global tax on all digital companies; Amount A targets only the largest groups. It is not the same as Pillar Two; the global minimum tax is a separate, further-advanced workstream addressed in its own right. And it does not, by itself, eliminate the relevance of holding-company jurisdictions or treaty planning; it changes the calculus at the very top of the size scale while leaving most international structuring questions intact.

The honest summary is that Pillar One is a profound idea whose final legal shape is still being negotiated. Planning around it means planning around a moving target, with conservative assumptions and a readiness to adjust.

How HPT helps

We help internationally active businesses and their advisers assess whether they fall within Pillar One's scope, model the potential effect of Amount A and Amount B alongside Pillar Two, and stress-test existing structures against a tax world that increasingly follows markets and substance rather than form. Where clients are comfortably below the thresholds, we say so plainly and focus attention where it belongs.

If you would like a clear read on whether these reforms touch your structure, we are happy to talk it through.