1. Introduction
Competition law is primarily enforced by public authorities. As part of the public law enforcement mechanism, administrative authorities identify, investigate and sanction infringements, while natural and legal persons are positioned not as direct actors in the process but as parties that bear its consequences. By contrast, private enforcement constitutes a mechanism through which natural and legal persons harmed by competition infringements may seek compensation before courts through damages actions. Today, these two mechanisms are regarded not as alternatives but as complementary to each other.
In this article, “follow-on actions” refers to damages actions brought by parties harmed by a competition infringement after it has been established by the competent authorities. Since the infringement is typically already established by administrative decisions, the proceedings focus on harm and causation. In this respect, follow-on actions serve as a functional bridge between public enforcement of competition law and private compensation mechanisms.
Over the past two decades, there has been a significant global rise in the private enforcement of competition law, especially in damages actions. This rise is driven by growing awareness that competition infringements harm not only public order but also individual interests. The long-established practice of damages actions in the United States (“US”) has influenced many legal systems, particularly in Europe, where substantive and procedural rules facilitating access to courts for injured parties have become increasingly common. As a result, competition law enforcement is no longer confined to public sanctions but is also reinforced by private damages actions.
2. Approaches to Compensation for Damages under European Union and Turkish Law
The European Union (“EU”) has long operated within a system in which public enforcement was dominant; however, over time it has adopted a policy orientation that strengthens private damages actions aimed at compensating harm arising from competition law infringements.[1] At the center of this shift lies Directive 2014/104/EU on antitrust damages actions (“Directive”), a key instrument designed to facilitate claims for compensation by injured parties. The Directive introduced significant reforms, including a recalibration of the burden of proof, expanded access to evidence, harmonization of limitation periods, and, in particular, presumptions regarding the existence of harm in cartel cases. As a result, private damages actions have become an essential complementary pillar of EU competition law enforcement.
In Türkiye, competition law enforcement is still largely shaped by a public enforcement model. Investigations conducted by the Turkish Competition Authority and administrative fines remain at the core of the system. Nevertheless, the private law consequences of infringements of the mandatory provisions of Law No. 4054 on the Protection of Competition (“Law No. 4054”) are regulated in Articles 56–59 under the heading “Civil Law Consequences of Restrictions of Competition,” which govern invalidity, the right to damages, compensation of harm, and the principles of burden of proof. In practice, however, these mechanisms remain limited in application.
Against this background, developments in the EU, particularly the framework introduced by the Directive, serve as an important reference point for Turkish law as well. The need to develop public enforcement and private damages actions in a balanced and mutually reinforcing manner in order to enhance the effectiveness of competition law is increasingly emphasized in both doctrine and practice.
3. Competition Law Infringements and Damages Under EU Law
Under EU law, full compensation covers actual loss (damnum emergens), loss of profit (lucrum cessans), and interest[2]. However, compensation must not lead to overcompensation. In order to understand the EU’s approach to competition law infringements, it is particularly important to examine the recitals of Directive 2014/104/EU. The Directive states, in essence, that compensation for harm caused by competition law infringements is a key tool for ensuring the effective enforcement of EU competition rules. It recognizes that divergences among Member States’ procedural and substantive rules—particularly regarding access to evidence, limitation periods, joint and several liability, presumptions of harm in cartel cases, and the passing-on defense—may hinder effective damages actions. On this basis, the Directive aims to facilitate claims for damages by persons harmed by competition law infringements and to ensure the proper functioning of the internal market. [3] Accordingly, its primary objective is to enhance access to compensation for injured parties while supporting effective public enforcement.
Article 16 of the Directive, as a provision that fundamentally transforms the evidentiary regime in competition law damages actions, has particularly paved the way for the consolidation of follow-on actions. Its core effect is to ensure procedural economy by preventing the re-litigation of an infringement already established at the administrative level before civil courts, thereby enhancing legal certainty. Accordingly, in damages actions following cartel decisions of the European Commission and national competition authorities, courts refrain from re-examining the existence of the infringement, allowing claimants to focus solely on harm and causation. In addition, Article 16(2) introduces a cross-border effect by granting at least evidentiary value to decisions of other Member States’ authorities. While it does not establish full binding effect, it creates a hybrid model that strengthens the circulation and evidentiary weight of decisions within the EU.
Article 17, by contrast, takes into account the inherently complex nature of competition law damages, which often require economic modelling, and relaxes traditional rules of evidence in favor of claimants. It states: “It shall be presumed that cartel infringements cause harm. The infringer shall have the right to rebut that presumption.” This presumption of harm in cartel cases is based on the economic understanding that cartels typically lead to price increases or welfare losses, and it significantly reduces the claimant’s burden of proof. This approach is also consistent with “the principle of effectiveness” developed in the case-law of the Court of Justice of the European Union, according to which the exercise of rights arising under EU law must not be made excessively difficult or practically impossible due to national procedural rules. Moreover, the power granted to courts to estimate the amount of harm ensures that compensation becomes practically enforceable in cases where precise quantification is difficult. In this context, Articles 16 and 17, when read together, show that the Directive establishes an evidentiary regime that not only recognizes substantive rights but also guarantees their practical enforceability.
4. Competition Law Infringements and Damages Under Turkish Law
A review of Turkish judicial practice shows that courts tend to assess damages claims arising from competition law infringements within the framework of tort liability[4]. Indeed, case-law accepts that such actions are based on tort principles and emphasizes that the claimant must prove the elements of unlawful act, damage, fault, and causal link. In this context, it is also noteworthy that some judicial decisions have mitigated the burden of proof regarding fault. In particular, with respect to anti-competitive agreements, concerted practices, or abuse of dominant position, it is stated—consistent with the prevailing view in doctrine—that fault may be presumed[5].
Judicial decisions also concretize the relationship between the public and private enforcement dimensions of competition law. In this respect, it is observed that infringement decisions issued by the Competition Authority play a significant role in private damages actions. In particular, decisions of Regional Courts indicate that the finding of an infringement by the Competition Board effectively constitutes a precondition for the case and that such decisions carry strong evidentiary value before civil courts[6][7]. This case-law suggests an influence of the EU Directive approach on Turkish law.
In addition, some decisions explicitly demonstrate that administrative sanctions and private law compensation mechanisms function together to ensure the effectiveness of competition law. Courts awarding triple damages under Article 58 of Law No. 4054, based on infringement findings by the Competition Board, illustrate how public enforcement is reinforced through private law remedies. In practice, it is also evident that administrative proceedings concerning competition law infringements have a direct impact on private law claims. In this context, courts commonly stay damages proceedings until annulment proceedings against Competition Board decisions are concluded. Where an administrative court annuls the Board’s decision, this may lead to the rejection of related private damages claims[8].
At the same time, some case-law maintains a clearer separation between public and private law spheres. The 13th Chamber of the Council of State has distinguished competition allegations from unfair competition and referred them to civil courts[9], while the 14th Chamber of the Regional Court has supported the primacy of administrative review[10]. In one decision, the Competition Board stated that “the purpose of competition law is not to protect individual interests but to ensure and safeguard a competitive market structure in the public interest. Complaints serve to bring to the Board’s attention possible infringements of which it may not be aware and to enable it to take action. While a complainant may expect and even obtain certain benefits from this process, such benefits remain secondary to the public interest.” This approach clearly demonstrates that the complaint mechanism is primarily designed to protect the public interest rather than individual interests.[11] In other words, when assessing the purpose and effects of complaints, the Board emphasizes that the primary objective is the protection of the competitive market structure and the public interest, and any potential benefit to the complainant plays only a secondary role. This approach clearly demonstrates that, within Türkiye’s competition law system, the primary objective of public enforcement is the protection of the public interest.
This divergence highlights the tension between separation of spheres and the need for balanced integration. Despite doctrinal emphasis on complementarity between public and private enforcement, practice continues to preserve the primacy of administrative enforcement, thereby limiting the autonomy of private damages actions and reinforcing the need for a more coherent and harmonized development.
5. Assessment of Follow-on Actions Under Turkish Law
In competition law, “follow-on actions” refer to damages claims brought by persons alleging harm from a competition law infringement after the infringement has been established by the competent administrative authority. These actions are distinguished from “stand-alone” actions, which are brought in the absence of any prior administrative finding of infringement. Follow-on actions therefore serve to strengthen the link between the establishment of an infringement and the compensation of individual harm.
At the EU level, the system introduced by the Directive, particularly through Articles 16 and 17, establishes a framework that structurally enhances the effectiveness of private enforcement. By contrast, although Law No. 4054 explicitly recognizes the right to claim damages, Turkish law does not provide comparable procedural and evidentiary tools facilitating its exercise. In the EU system, the binding effect of competition authority decisions as to the existence of an infringement (Article 16) significantly alleviates the claimant’s burden of proof in follow-on actions. In Turkish law, however, there is no explicit rule granting binding effect to Competition Authority decisions before civil courts. Although such decisions are treated as strong evidence in practice, they do not have res judicata-like effect for the judge. In legal practice, res judicata entails prohibition of re-litigation, binding force, and conclusive evidentiary effect[12]. This situation effectively brings the infringement itself back into issue, increasing litigation costs and weakening the deterrent function of private enforcement.
Similarly, Article 17 of the Directive introduces a presumption that cartels cause harm and empowers courts to estimate damages, thereby recalibrating the burden of proof in favor of claimants. In Turkish law, although courts possess discretion within general evidentiary principles, there is no cartel-specific legal presumption of harm. This gap places a significant evidentiary burden on claimants, particularly in cases requiring complex economic analysis. Accordingly, while Turkish law recognizes the right to compensation in substantive terms, the absence of EU-style evidentiary facilitation mechanisms limits the effectiveness of private enforcement. In this respect, Articles 16 and 17 of the Directive may serve as normative reference points for potential reform in Turkish law.
Although the development of follow-on actions in Türkiye is still at an early stage, recent case-law and doctrinal discussions indicate a gradual evolution in this field. In particular, the recognition of Competition Board decisions as “strong evidence” before civil courts creates a de facto practice resembling the follow-on model. Even though such decisions do not have explicitly defined binding force, courts’ tendency to refrain from re-examining the infringement in depth and to focus primarily on damage and causation suggests the emergence of an implicit follow-on approach in practice.
However, this development has not yet been systematized. In particular, (i) limited access to evidence, (ii) insufficient development of expert infrastructure for complex economic damage assessment, and (iii) the absence of an explicit presumption of harm remain key factors restricting the expansion of follow-on actions. In addition, the suspension of civil proceedings pending the outcome of annulment actions against Competition Board decisions prolongs litigation and reduces the effectiveness of private enforcement. It should also be noted that in tort-based competition claims, the limitation period running from the moment the injured party becomes aware of the infringement may also result in loss of rights for claimants.
6. Conclusion
The relationship between public and private enforcement mechanisms in competition law has developed on the basis of complementarity. In the EU, the Directive has made private damages actions—particularly follow-on actions—a structural element that enhances the effectiveness of the system. In this framework, the link between the establishment of an infringement and the compensation of harm has been strengthened, and private enforcement has been positioned as a functional tool that complements the activities of public authorities.
In Turkish law, although the right to claim damages is recognized, the procedural and evidentiary tools facilitating its exercise remain limited. Nevertheless, the fact that Competition Board decisions are treated as strong evidence in practice, and that courts base their assessments on such decisions, indicates a gradual development of a follow-on-like structure. Although this situation is not based on an explicit binding regime, practice appears to be increasingly converging with the EU approach, and the importance of private enforcement is correspondingly growing.
Against this background, in order to enhance the effectiveness of damages claims arising from competition law infringements, it is essential to develop mechanisms that balance the burden of proof, facilitate access to evidence, and expedite proceedings. Potential developments in this direction would contribute to a more effective and predictable framework for private enforcement under Turkish competition law.
Ayça Buse Kendir, Associate
[1]Antitrust Damages Directive 2014/104/EU, Recital 3; European Commission, White Paper on Damages Actions (2008); Green Paper (2005).
[2] Antitrust Damages Directive 2014/104/EU, Article 3, Right to full compensation.
[3] Antitrust Damages Directive 2014/104/EU, Recital 5, 6, 7, 9.
[4] Istanbul 16th Commercial Court of First Instance, File No. 2016/1281; Istanbul Anadolu 6th Commercial Court of First Instance, File No. 2018/274
[5] Istanbul 12th Commercial Court of First Instance, File No. 2017/218
[6] Istanbul Regional Court, 45th Civil Chamber, File No. 2022/1579; 14th Civil Chamber, File No. 2019/1922
[7] Istanbul 12th Commercial Court of First Instance, File No. 2017/218, Decision No. 2025/748, 16.10.2025
[8] Istanbul 3rd Commercial Court of First Instance, File No. 2016/1231; Court of Cassation, 3rd Civil Chamber, File No. 2023/4497
[9] Council of State, 13th Chamber, File No. 2020/1756, Decision No. 2024/2675, 10 June 2024
[10] Istanbul Regional Court, 14th Civil Chamber, File No. 2019/1922, Decision No. 2022/383, 31 March 2022
[11] Decision No. 24-54/1211-517, 20.12.2024, Y.T. 24.04.2025
[12] Kemal Gözler, “Res Iudicata’nın Türkçesi Üzerine”, Ankara Üniversitesi Hukuk Fakültesi Dergisi, Volume 56, Issue 2, 2007, pp.45-61.
