U.S.-Style Multi-Claimant Actions Take Another Step in the U.K.: Le Patourel v BT, the First U.K. Opt-Out Judgment Goes to the Defense

In December 2024, the U.K. Competition Appeal Tribunal handed down its defense ruling in Le Patourel v BT—the first opt-out, collective action trial in the United Kingdom.

Dechert has been following recent developments in English law that are attracting mass tort and multi-claimant litigation. Since we began covering these trends, England has witnessed a notable increase in mass action filings, indicating a shift toward U.S.-style litigation. Yet many differences remain between the U.S. and English legal systems—one key distinction being that trials in England are decided by judges rather than juries. The Competition Appeal Tribunal’s (“CAT’s”) recent trial ruling in Justin Le Patourel v BT Group [2024] CAT 76—unanimously dismissing the collective claim—offers insights into how multi-claimant actions may develop going forward.

The CAT opt-out multi-claimant regime (akin to U.S.-style opt-out class actions) was established in 2015. Before a claim can proceed, it must first pass a certification process, where the CAT determines whether to issue a collective proceedings order. This process serves as a gatekeeping mechanism, similar to class certification in the United States, ensuring that claims meet criteria for cohesion and suitability for collective proceedings.  In recent years, mass claims alleging abuse of a dominant market position have been filed at an increasing rate in the CAT.

The Le Patourel claim involved over 3.7 million customers who alleged that BT (a British telecommunications company) had abused its dominant position by charging excessive prices for residential telephone landline services, seeking over £1 billion in damages. Le Patourel is significant as it marks the first opt-out collective action before the CAT to proceed to a trial on the merits and to reach a substantive judgment.

Although the CAT agreed that BT’s prices surpassed a competitive benchmark, it ultimately ruled them not “unfair,” finding no abuse of dominance. The CAT’s reasoning in Le Patourel highlights the rigorous review that parties can expect in the future. For example, the CAT evaluated competing methodologies presented by experts on both sides (which is atypical as non-partisan expert evidence is the norm in English courts) and ultimately combined aspects from each to reach its decision, rather than adopting a single model. This approach illustrates the CAT’s proactive engagement with complex evidence and its reliance on its own analysis and expertise to resolve disputes, creating valuable precedent for litigants to turn to in future cases.

Despite clearing the certification hurdle, the Le Patourel claim faced a far more challenging test at trial, demonstrating that initial approval does not guarantee success on the merits. The judgment demonstrates that the CAT is prepared to scrutinize both legal and factual arguments comprehensively. As additional multi-claimant actions head toward trial in England, businesses should prepare to defend their practices on multiple fronts with clear data, robust expert submissions, and a cohesive narrative.