by Grigoris Bacharis, Lecturer in Private Law, Edinburgh Law School
I. Introduction
I begin with a broad claim that I cannot fully defend here,[1] but wish to illustrate in part: significant areas of European delict (or tort) law are undergoing a subtle but meaningful transformation. Across domains such as environmental harm, data protection, and competition enforcement, delictual claims are increasingly mobilised to serve regulatory aims. As scholars like Kysar have noted, claimants are no longer simply seeking redress for private wrongs.[2] They are enforcing public norms through private litigation.
This shift gives rise to what might be called enforcement or regulatory delicts: private actions that retain the formal structure of delict law but pursue objectives—deterrence, compliance, and systemic accountability—that are quintessentially public. The trend is inspired mainly by American legal practice, where private enforcement, via torts, federal claims, mass litigation, and settlements, is widespread and arguably expanding.[3]
In response, the structural doctrines of delict law in many European jurisdictions, especially those governing attribution of responsibility, are being reshaped. The development unsettles foundational commitments of private law, notably the principle that liability must be borne on the basis of wrongdoing, the wrongdoer must bear that liability, and that legal personality serves as the foundation of attributing liability. Increasingly, the primary purpose of these claims is not to apportion interpersonal responsibility or protect rights but to enforce public policy.
Competition damages actions offer a vivid illustration of this development. While formally rooted in national delict law under the EU’s principle of procedural autonomy, these claims are animated by goals of deterrence and regulatory compliance. To that end, core rules, such as those on standing and fault, have been adjusted to better align with enforcement aims.
A particularly striking innovation appears in the use of the doctrine of the undertaking—an economic unit comprising a group of corporate entities rather than a legal person—as the liable subject.[4] Initially introduced by the Court of Justice in the context of public enforcement and now expanded to private claims, this doctrine adopts a functional approach that bypasses the traditional responsibility framework of private law. It permits liability to be imposed within a corporate group, sometimes on completely innocent subsidiaries, for acts committed by their parents. In doing so, it disregards the twin pillars of legal personality and limited liability, assigning responsibility without requiring that the legal person that bears the liability itself committed the wrong.
This is the first of two posts examining this doctrinal shift. My aim here is to explore why it occurs in competition law specifically, why it challenges the foundations of delict and why I consider it a source of doctrinal tension. The central claim is that the undertaking doctrine introduces intra-group liability that sits uneasily within a legal framework built on personhood, agency, and normative justification. It stretches to its logical conclusion one of the most basic principles of private law—legal personality—and does so in the name of enforcement. This shift shows a trend toward private litigation serving regulatory roles in a mix of public and private law.
This development is significant, as it represents the most prominent erosion of the principle of legal personality in private law and the most expansive application of enterprise liability to date. The field of competition damages is likely to become a particularly influential area in the UK and Europe, serving as a gateway for the broader introduction of mechanisms such as litigation funding, non-compensatory remedies, and group actions.[5] In what follows, I outline the contours of the undertaking doctrine in EU competition law, trace its migration into private enforcement, and then assess its implications for the coherence of delict’s foundational principles, while also considering why certain areas of delictual liability may prove more receptive to this form of group liability.
II. The ‘Undertaking’ as a Functional Legal Subject
In both EU and UK competition law, the concept of the undertaking defines the relevant subject of legal responsibility.[6] It encompasses any entity engaged in economic activity, regardless of legal form or corporate structure. The undertaking, or single economic unit, defines the personal scope of application of EU and UK competition law.
This abstraction has concrete effects, preventing firms from evading liability through corporate restructuring or fragmentation. It enables the European Commission to hold parent companies liable for infringements committed by their subsidiaries, to disregard intra-group shields even in cases when a company has a minority share in another, and to maintain continuity of liability across corporate transformations. The undertaking, then, is not a legal person. It has no assets, no organs, and no board. It is an economic fiction imposed by courts to facilitate deterrence.
In recent years, we’ve witnessed a shift from public to private enforcement in competition law. The EU Damages Directive (2014/104/EU)—which continues to influence the UK—and the rise of follow-on and standalone claims have created a new frontier for private enforcement. Private claims, based on delictual or tortious grounds (such as the tort of breach of statutory duty), are becoming very widespread, but this expansion raises foundational questions.
What happens when a regulatory concept like the undertaking is imported into private law? That question came to a head in Skanska Industrial Solutions Oy (C-724/17). There, the ECJ held that the undertaking doctrine applies not only to public enforcement but also to private damages actions. The Court reasoned that the right to damages under EU law must be effective, and that effectiveness demands continuity of liability, even after legal restructuring.
This logic was taken further in Sumal (C-882/19), where a subsidiary was held liable for cartel conduct by its parent. The Court reasoned that because the two operated as part of the same economic unit and participated in the same market, the subsidiary could be liable, even if it had not committed the wrong itself.
In MTB/Heineken (2025), the ECJ reaffirmed the principle. A Greek firm sued the Dutch parent company in the Netherlands. The Court held that a parent company and its subsidiary may be presumed to constitute a single undertaking, making the parent jointly liable for the subsidiary’s conduct on the basis of “decisive influence” inferred from ownership. Crucially, it confirmed that this presumption applies not only in administrative enforcement but also in private claims and may serve to establish jurisdiction under EU law.
Together, these decisions, which UK courts seem to apply too, have profound implications.[7] They suggest that national delict law must now accommodate a liability regime in which responsibility is assigned to an abstract economic unit. Legal persons who played no causal role in the infringement may therefore be held liable
III. Legal Personality and the Structure of Responsibility
Traditional delict law is structurally committed to legal personality.[8] Liability presupposes that the defendant is a bearer of rights and obligations, a person (natural or legal) capable of wrongdoing. This is more than a formality. It embodies private law’s normative architecture.
Courts are therefore cautious when piercing the corporate veil in delictual situations.[9] Liability arises through agency, fault, or voluntary assumption of responsibility. As corrective justice theorists have argued, delict law is not merely instrumental. It is a normative structure that governs relationships between persons.[10]
The use of the undertaking doctrine disrupts this structure. It allows for group or successor liability without linking it to individual conduct, fault, or assumption of responsibility. This might help pursuers avoid the abuse of the corporate form but runs against received traditions in corporate theory—such as real entity theory—which view corporations not as legal fictions but as autonomous legal actors.[11] Scholars such as Micheler have shown how corporate personality enables coherent attribution of rights and obligations.[12] By ignoring personality, the undertaking doctrine risks unpredictable and arbitrary liability. If liability is detached from the framework of personality, the coherence of both corporate and private law might be jeopardised, since courts may substitute ad hoc functional reasoning for principled attribution based on wrongdoing.
The UK’s recent environmental, social and governance cases —Vedanta and Okpabi—demonstrate the resilience of private law’s commitment to personal responsibility. The Supreme Court allowed [tort] claims against parent companies to proceed, but only where the parent had assumed responsibility through its own actions. Group membership alone was not sufficient. A similar logic underpins resistance to the EU’s Corporate Sustainability Due Diligence Directive (CSDDD). That Directive would allow civil liability across value chains, based on whether a parent company ‘contributed to’ or ‘incentivised’ harmful conduct. But here, too, the shift away from control or fault and towards influence has been sharply contested.
IV. Is This Vicarious Liability in Disguise?
The undertaking doctrine is sometimes framed as a new form of vicarious or enterprise liability.[13] But this comparison obscures as much as it reveals. Vicarious liability traditionally involves a primary wrongdoer and a secondary party who is held liable because of a defined relationship, typically employment. In corporate groups, by contrast, it is often unclear who the wrongdoer is, what relationship justifies attribution, or even what kind of wrongdoing has occurred. More importantly, the undertaking doctrine does not presuppose a wrongful act by a legal person at all. It operates at the level of the economic unit. This is not veil-piercing; it is something more radical. In this sense, liability may arise either without any wrong being attributable to a specific legal person, or by holding some legal persons liable for the wrongs of others, not through ordinary attribution but by virtue of their membership in the economic unit. The law looks through the legal person, not to locate responsibility, but to assign liability based on structural considerations. Responsibility is imposed based on economic integration, not individual action or fault. The result is a form of strict regulatory liability, a concept foreign to private law’s emphasis on wrongdoing, volition, and justification. As Feng has observed, many of the rationales traditionally used to justify vicarious liability do not necessarily apply in this context.[14] Accordingly, the undertaking doctrine is better understood not as an expansion of vicarious liability, but as a distinct form of intra-group regulatory liability.
Whether one sees this expansive form of delictual liability as a problem or an advantage depends on one’s view of delict law. If one sees it as an instrument of regulation, this functional approach may appear appropriate. But if delict law is about interpersonal justice, where responsibility tracks action, then this shift is deeply problematic.
So why does it happen here, and not elsewhere? Why is the principle of legal personality set aside here, yet preserved in most other areas of delict, including the otherwise far-reaching ESG cases? One possibility is that legal personality can be treated as a mere formality where necessary. Yet this is not how most areas of delict law operate. Courts generally respect legal personhood, particularly in the attribution of responsibility within corporate structures. Another suggestion might be that there is a broader movement toward disregarding legal personality.[15] But if such a trend exists, it is uneven and contested. Outside of competition law, delictual doctrines tend to retain personhood as the foundation for liability. In short, this is not a generalised pattern. So why here, and not elsewhere?
V. The Public Law Logic of Enforcement Delicts
The answer may lie in the emergence of the enforcement delicts: private claims designed to support public enforcement. Competition damages actions, particularly under EU law, are one example. Environmental and human rights torts (often linked to ESG litigation) may be others.
These claims often target large corporate groups whose fragmented legal structure impedes accountability. As Mariana Pargendler has argued, corporate law facilitates “regulatory partitioning”—the separation not just of assets, but of legal and regulatory obligations between the corporation and its shareholders or affiliates. This partitioning enables firms to shield liability through formal entity boundaries. Functional legal tools such as the undertaking doctrine respond by collapsing these partitions through what Pargendler calls ‘veil peeking’: a context-specific override of corporate separateness in service of regulatory goals. This dynamic is particularly evident in enforcement delicts, where liability is not grounded in interpersonal wrongdoing but in the public law rationale of securing compliance and systemic deterrence.
Thus, the shift away from person-based liability is explained by the regulatory and public-facing nature of these delicts. But in doing so, they shift liability away from persons and toward economic abstractions. The aim is deterrence, not responsibility.
The CSDDD exemplifies this logic. It anticipates private enforcement as a mechanism for ensuring corporate accountability. Victims can sue parent companies for harms caused by subsidiaries or suppliers, even across borders. These are delictual claims in form, but they serve regulatory goals. The same may be true for actions in areas spanning environmental harm, data protection, and AI; the shift in corporate group liability might find fertile ground for expanding further.
This raises a pressing question: should private law of delict and tort accommodate this shift by abandoning its structural commitments? Or can it instead develop principled frameworks for group responsibility that preserve legal personhood while recognising real-world integration and benefit? That question will be the subject of a second post.
[1] See however G Bacharis, ‘Framing Civil Actions for Wrongs as a Spectrum: From Tort Law to Pure Enforcement’, in A Robertson & J Neyers (eds), Private Law and the State (Hart Publishing, 2024) 251.
[2] See DA Kysar, ‘The Public Life of Private Law: Tort Law as a Risk Regulation Mechanism’ (2018) 9 European Journal of Risk Regulation 48.
[3] RA Kagan, Adversarial Legalism (HUP, 2019).
[4] On the definition of corporate groups see CA Witting, Liability of Corporate Groups and Networks (CUP 2018) 3-4.
[5] R Mulheron, ‘Further Impetus for a Statutory Class Action, post-Lloyd v Google’ (2023) 42 CJQ 10.
[6] See P Whelan, Parental Liability in EU Competition Law: A Legitimacy-Focused Approach (OUP 2023).
[7] See generally S Daly and A Jones, ‘The Undertaking and Single Economic Entity Concepts in EU and UK Competition Law: Proposals for a Refined Approach’ in Florian Thépot and Anna Tzanaki (eds), Research Handbook on Competition and Corporate Law (Edward Elgar 2025) 128.
[8] See generally B Ewing, ‘The Structure of Tort Law, Revisited: The Problem of Corporate Responsibility’ (2015) 8(1–2) Journal of Tort Law 1.
[9] PTF Yiu, ‘Piercing the Corporate Veil Post‑Prest’ (2024) Law and Financial Markets Review 1.
[10] See generally E Weinrib, The Idea of Private Law (HUP 1995).
[11] J Hardman, ‘Fixing the Misalignment of the Concession of Corporate Legal Personality’ (2023) 43 Legal Studies 443.
[12] E Micheler, Company Law: A Real Entity Theory (OUP 2021).
[13] A Kalintiri, ‘Revisiting Parental Liability in EU Competition Law’ (2018) 43(2) European Law Review 145.
[14] X Feng, ‘The Extension of Vicarious Liability in Corporate Groups’ (2024) 24(1) Journal of Corporate Law Studies 169.
[15] See however A Dignam and PB Oh, ‘Disregarding the Salomon Principle: An Empirical Analysis, 1885–2014’ (2019) 39 OJLS 16 (22).
