Key Takeaways
- • Michael Platt, billionaire founder of BlueCrest Capital Management, filed professional negligence proceedings against tax barrister Malcolm Gammie KC of One Essex Court, alleging negligent legal advice in a long-running HMRC dispute.
- • The claim, filed in September 2025, centres on whether Gammie should have advised advancing arguments based on the clients' Swiss tax residency, which Platt and BlueCrest say would have offered a different defence.
- • BlueCrest suffered a Court of Appeal defeat in 2023 over the taxation of partner incentive payments made to senior traders, and a UK Supreme Court ruling in July 2026 went against the firm on the employment tax status of its LLP members, potentially exposing it to a tax bill approaching £200 million.
- • At a Commercial Court hearing on Friday, 6 November, lawyers disputed whether bank and credit card statements dating back 17 years should be disclosed.
- • The allegations remain unproven and no trial date has been set.
Summary
Michael Platt, the billionaire founder of BlueCrest Capital Management, has brought professional negligence proceedings against leading tax barrister Malcolm Gammie KC of One Essex Court, according to the original report. The claim, filed in September 2025, follows BlueCrest's lengthy battle with HM Revenue & Customs over the tax treatment of payments made to senior traders under the firm's partner incentivisation plan.
Gammie represented Platt, BlueCrest and former finance chief Andrew Dodd during earlier tribunal proceedings. The dispute reached the Court of Appeal in 2023, where BlueCrest suffered a significant defeat over the taxation of the incentive payments. The negligence claim centres on whether Gammie should have advised his clients to advance arguments based on their Swiss tax residency, according to City AM's report. Platt and BlueCrest allege that this failure deprived them of an opportunity to pursue a different defence against HMRC.
The proceedings follow another major setback for BlueCrest. In July, the UK Supreme Court rejected the firm's arguments concerning the employment tax status of its LLP members, potentially exposing it to a tax bill approaching £200 million. That ruling concerned a separate tax issue from the one underlying the negligence claim.
At a Commercial Court hearing on Friday, 6 November, lawyers also disputed whether bank and credit card statements dating back 17 years should be disclosed as evidence. The allegations against Gammie remain unproven, and no trial date has been set.
Gammie represented Platt, BlueCrest and former finance chief Andrew Dodd during earlier tribunal proceedings. The dispute reached the Court of Appeal in 2023, where BlueCrest suffered a significant defeat over the taxation of the incentive payments. The negligence claim centres on whether Gammie should have advised his clients to advance arguments based on their Swiss tax residency, according to City AM's report. Platt and BlueCrest allege that this failure deprived them of an opportunity to pursue a different defence against HMRC.
The proceedings follow another major setback for BlueCrest. In July, the UK Supreme Court rejected the firm's arguments concerning the employment tax status of its LLP members, potentially exposing it to a tax bill approaching £200 million. That ruling concerned a separate tax issue from the one underlying the negligence claim.
At a Commercial Court hearing on Friday, 6 November, lawyers also disputed whether bank and credit card statements dating back 17 years should be disclosed as evidence. The allegations against Gammie remain unproven, and no trial date has been set.
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