Class Actions Radar:
United Kingdom – Competition

The landscape

The UK has a separate regime for collective claims based on infringements of competition law, which are heard by the Competition Appeal Tribunal (CAT).

Its scope was significantly expanded in 2015. Claims can be brought by a Class Representative on behalf of consumer or business claimants, seeking aggregate damages on either an opt-in or opt-out basis. Claims may be "follow-on", based on an existing decision by a competition regulator finding a competition law breach, or "standalone", without any underlying infringement decision. 

The landmark Supreme Court judgment in Merricks v Mastercard in December 2020 gave this avenue considerable momentum by setting a very low bar for certification of claims by the CAT (certification being the initial procedural hurdle before the claim can proceed to trial). Since then, there has been a significant increase in claims filed (30 have been filed in the last three years alone, compared to just 9 in the five-year period prior to the Merricks judgment).

Growth in competition class actions is further fuelled by increased availability of litigation funding (with the potential for significant returns proving very attractive to funders), broad disclosure rules and the CAT's willingness to engage in sophisticated economic analysis and detailed consideration of complex legal tests. No claims have yet resulted in an award of aggregate damages. Judgment in the first full trial of opt-out competition collective proceedings, Le Patourel v BT Group, was handed down at the end of 2024 and the claim was dismissed. A large number of further cases have passed through the certification stage and judgment is awaited in respect of a further three substantive trials, with further trials entering the CAT's diary on a regular basis.

There have also been a number of settlements reached, with one so far having resulted in distribution to class members.

As a result of all of this, ten years on from the regime's inception, we are only now starting to see evidence of the financial outcomes the regime can deliver.

Marking a decade since the regime was broadened, in August 2025, the UK's Department for Business & Trade announced a review of the collective proceedings framework and invited a "call for evidence" to examine whether and what changes to the regime may be beneficial. Although there is no expected date for the results of this review, its outcome could shape the future trajectory of collective proceedings in the UK.

Current developments

While we continue to see a number of "plain vanilla" follow-on claims, there is a growing trend towards standalone claims, often rooted in allegations of abuse of dominance but pursuing novel theories of harm.

Such claims often stem from a perceived regulatory gap, with Class Representatives being creative in arguing that claims involving matters such as consumer rights and data privacy – or even environmental issues – amount to an abuse of a dominant position, in order to claim aggregate damages under the opt-out collective competition claims regime. Recent examples have included claims in relation to mobile phone loyalty "penalties", "throttling" of iPhone batteries and alleged misreporting of sewage discharges by water companies (albeit the latter case was dismissed at the certification stage on the basis that the claim was ousted by sector specific legislation).

Class Representatives may also seek to use the opt-out regime to obtain redress for consumers where a regulator has adopted a forward-looking solution following a review of issues in a particular sector (such as a regulatory change or acceptance of voluntary commitments), without any compensation for those previously affected.