BlueCrest Capital Management, the hedge fund founded by billionaire Michael Platt, has declared the United Kingdom “no longer a serious contender” as a place to do business after losing a high-stakes tax battle that is expected to cost the firm roughly £200 million. The Supreme Court on Wednesday unanimously dismissed BlueCrest’s appeal against HM Revenue & Customs (HMRC), ruling that the vast majority of payments made to its senior traders were “disguised salary” and must be taxed as employee income rather than partnership profits.
The Ruling and What It Means
The decision brings to a close a legal dispute that has run for nearly four years over how BlueCrest compensated members of its limited liability partnership. Under the Salaried Member Rules — legislation introduced in 2014 to prevent tax avoidance by LLPs — a member must be treated as an employee for income tax and National Insurance purposes if three conditions are met. First, at least 80 per cent of the member’s pay is a “disguised salary”, meaning it is fixed or varied without direct reference to the partnership’s overall profits or losses. Second, the member does not have “significant influence” over the affairs of the LLP. Third, the member’s capital contribution is less than 25 per cent of that disguised salary.
The Supreme Court upheld the findings of lower courts that BlueCrest’s structure satisfied all three conditions. While the traders had operational responsibilities within the firm, the court found their governance role was minimal and that their remuneration was not genuinely tied to the partnership’s profit-and-loss account. Most of the payments were therefore “disguised salary”, leaving BlueCrest liable for an estimated £143 million in income tax and more than £55 million in National Insurance contributions for the period between 2014 and 2019.
BlueCrest had argued that its members’ pay was linked to the LLP’s profits and that they exercised significant influence over the firm. HMRC countered that the fixed nature of the remuneration and the lack of genuine exposure to losses meant the traders were effectively employees. After the ruling, an HMRC spokesperson said: “We welcome the Supreme Court’s decision, which confirms how the Salaried Member Rules should be implemented. As always, we will consider if any updates should be made to our guidance in light of this judgment.”
BlueCrest’s Criticism of the UK Business Environment
In a strongly worded statement issued after the judgment, BlueCrest said that HMRC’s published guidance on the Salaried Member Rules “was wrong” and that businesses in the United Kingdom require certainty when organising their tax affairs. “Without that certainty, and in an increasingly competitive global market, the UK is no longer a serious contender as a jurisdiction in which to do business,” the firm said.
The hedge fund’s criticism echoes broader disquiet among financial-services leaders about the direction of UK tax policy. Other prominent figures, including Alex Gerko, the billionaire founder of quantitative trading firm XTX Markets, and Paul Marshall, founder of the hedge fund Marshall Wace, have separately voiced frustrations with the tax regime after losing their own legal disputes or warning that reforms risk driving talent abroad. London’s overall tax rate for financial services firms is already higher than that of rival centres such as New York, Dublin, Frankfurt and Amsterdam, and concerns have mounted that the abolition of the non-dom regime and changes to carried interest taxation may further erode the capital’s competitive edge.
BlueCrest was founded in 2000 by Michael Platt and William Reeves. Platt, a British billionaire whose net worth Forbes estimates at $20.9 billion as of 2026, studied at the London School of Economics and worked as a proprietary trader at JPMorgan Chase before launching the fund. Reeves, an American with degrees from Yale and New York University, specialised in derivatives and macro strategies and retired from operational duties in 2007, selling his remaining partnership interests in 2011. BlueCrest once managed more than $35 billion in external assets, but in 2015 it returned client money and converted into a family office, managing only the wealth of its partners and employees — a shift that allowed it to adopt a higher-risk strategy.
The case is the latest in a series of Supreme Court rulings that have clarified employment status for tax purposes. In a separate judgment last year involving football referees, HMRC v Professional Game Match Officials Ltd, the court also addressed questions of mutuality of obligation and control. Legal observers say these decisions underscore the complexity of determining employment status and reinforce the case for statutory reform. For now, however, BlueCrest must shoulder its hefty tax bill — and its founder has made plain that the firm no longer sees Britain as a place where serious business can be done. The HMRC spokesperson added that the department would “consider if any updates should be made to our guidance in light of this judgment”.
