Windfall taxes in a global market: knowing where the UK’s reach ends

Windfall taxes are back in the headlines. In the energy sector in particular, they have become a recurring political response to exceptional profits, especially where those profits appear to arise not from new investment or innovation, but from war, supply disruption or sharp movements in global commodity prices.

The concept is simple enough. Where a company benefits from events outside its control, there is a moral and political argument that part of that upside should be captured by the state and used to support households, fund public services or accelerate the energy transition.

That argument has force. But it is also where the analysis often becomes too blunt.

The recent focus on BP’s profits is a useful case study. Its latest results have again prompted questions about whether energy companies should be paying more UK tax when global instability pushes oil prices higher. The optics are obvious: at a time of continuing pressure on households and businesses, exceptional profits made during a period of conflict and uncertainty are politically difficult to defend.

But BP is not just a British oil producer extracting from the North Sea. It is a global energy group, with operations, assets, trading activities, and commercial risks spread across multiple jurisdictions. That distinction matters.

The problem with windfall taxes is not that they tax windfalls. The problem is when governments confuse a genuine UK windfall with a global profit pool they do not control.

The starting point must be the tax base. The UK already has a windfall tax for UK oil and gas production. The Energy Profits Levy was introduced in 2022 and is currently charged at 38%, on top of Ring Fence Corporation Tax at 30% and the Supplementary Charge at 10%. That gives a headline tax rate of 78% on UK upstream oil and gas profits. That is not a light-touch regime. It is already a very material claim by the UK Exchequer on profits derived from UK natural resources.

Where the debate starts to lose precision is when it assumes that because a company is British-headquartered, listed in London, or simply profitable, the UK should be able to tax all of its global profits. That is not how international tax works.

Profits are generally taxed where the assets, people, risks and economic activity are located. The OECD’s BEPS framework and transfer pricing rules are designed to prevent artificial profit shifting and to align profits with value creation. They are not designed to give one country a free hand to tax profits properly attributable to overseas operations.

That distinction is critical. The UK should absolutely tax UK profits properly. It should also police artificial profit diversion robustly. But simply asserting that large multinational groups should pay more UK tax on global profits is not a serious tax policy. It is politics dressed up as economics.

Even its name deserves scrutiny. The UK’s “windfall” tax has now been in place since 2022 and is currently scheduled to run until 31 March 2030, subject to the relevant price mechanism. Nearly four years on, it is increasingly difficult to characterise it as purely temporary or exceptional. At some point, a windfall tax stops being a windfall and starts to look like part of the baseline.

It also raises a more uncomfortable question: to what extent have households ever been direct beneficiaries of this tax in practice?

A stable, temporary, price-triggered tax on UK resource rents is one thing, although “temporary” is increasingly open to question. A politically driven attempt to tax a global group’s worldwide profits because it happens to be listed in London, or simply because it is profitable, is quite another.

The latter risks encouraging companies to move listings, management functions and future investment elsewhere. Even if they do not leave overnight, capital allocation decisions may shift. Future projects may be prioritised in jurisdictions perceived to offer greater stability. Over time, that can mean less investment, fewer high-value jobs and a smaller tax base.

It is difficult to see how that supports growth or the creation of high-value jobs in the UK.

The better question is how the UK builds a tax and investment regime that captures fair value from its natural resources while still attracting capital, energy investment and entrepreneurial activity. At present, the UK appears far more reactive to headlines than focused on long-term policy design.

This tension is not unique to the UK, but pointing to other jurisdictions does not resolve it. If anything, it underlines the need for the UK to take a more considered approach. Expanding the tax base beyond where economic activity genuinely sits risks creating overlapping claims on the same profits, increasing complexity and uncertainty for businesses, and ultimately undermining the very investment the UK is seeking to attract.

This is not only a question for government. It is also a live issue for multinational businesses. Groups operating across borders need to understand not only the domestic tax rules in each jurisdiction, but how those rules interact with corporate residence, transfer pricing, supply chains, capital allocation and public scrutiny.

Bridging that gap requires more than technical compliance. It requires a clear understanding of how global businesses actually operate, and how tax, investment and structure fit together in practice.

That is where experienced international tax advice becomes critical. At Spencer West, we help clients navigate these cross-border issues in a way that is commercially effective, technically robust and defensible in an increasingly complex global tax environment.

Windfall taxes may make good headlines. But good tax policy, and good tax advice, require something more: knowing precisely what is being taxed, where the value is created, and where the UK’s reach properly ends.

Mark’s further commentary was published by Business & Accountancy Daily.