The Portugal chapter of the Lexology guide on Private Antitrust Litigation, written by Joaquim Caimoto Duarte and Sérgio da Conceição Ribeiro of the EU and Competition Law team at Gómez-Acebo & Pombo in Lisbon, provides a comprehensive overview of the remedies, liability framework and procedural mechanisms available to parties seeking redress for competition law infringements in Portugal. It further explains the scope of compensation available under the Portuguese Private Antitrust Act, as well as the rules governing interim relief, legal costs, joint and several liability, available defences and alternative dispute resolution mechanisms.
The chapter also highlights that undertakings found to have infringed competition law are required to provide full compensation for the harm caused, including both actual losses and loss of profit, together with late payment interest. Explaining as well, the presumption of harm applicable to cartel infringements and the tools available to courts when quantifying damages proves particularly complex, including the possibility of estimating such damages.
Joaquim and Sérgio also examine the procedural remedies available to claimants. In addition to damages actions, injured parties may seek interim measures where there is a risk of serious and irreparable harm, provided they can demonstrate both the likelihood of the right invoked and the urgency of the protection sought. The chapter notes that Portuguese law does not recognise punitive or exemplary damages in private competition litigation and that administrative fines imposed by the Competition Authority are not taken into account when calculating compensation.
Particular attention is devoted to the allocation of legal costs and the liability regime applicable to co-infringers. As a general rule, liability is joint and several, although specific protections apply to small and medium-sized enterprises and immunity recipients under leniency programmes. The guide also addresses contribution claims between co-infringers, the availability of the passing-on defence and the possibility of relying on general tort law defences in competition damages actions.
Finally, our team examines the topical issue of class actions under Portuguese law, together with consensual dispute resolution mechanisms, including arbitration and mediation, where legally permissible. By examining the principal remedies, procedural safeguards and liability rules governing private antitrust enforcement, the Portuguese contribution offers a practical overview of how competition law damages claims are pursued and defended before the Portuguese courts.
9 October, 2026
