Spain: An Intellectual Property: Patents Overview

The UPC’s Long Arm Over Spanish Validations of European Patents: Will the CJEU Limit its Reach?

One of the most salient trends in Spanish patent litigation concerns the extraterritorial reach of the so‑called long‑arm jurisdiction asserted by the Unified Patent Court (“UPC”). Under this approach, the UPC has declared itself competent to hear infringement actions relating to non‑unitary European patents where the alleged effects occur in States that are not parties to the UPC Agreement (“UPCA”), including patents validated in Spain.

In certain scenarios, such assertions of jurisdiction may be accommodated within the framework of Regulation (EU) No 1215/2012 (“Brussels I Recast”). In other cases, however, the UPC appears to be adopting expansive and controversial interpretations of the applicable jurisdictional rules. This is illustrated, for example, by the application of the anchor defendant doctrine. Under this approach, where the authorised representative appointed for CE‑marking purposes is domiciled in a UPCA Contracting State, that circumstance has been considered sufficient to confer jurisdiction on the UPC to adjudicate alleged infringements of a European patent validated in a non‑UPCA State, such as Spain, even where the infringing acts are allegedly committed by a third party not domiciled in a UPCA State, who may nevertheless be sued before the UPC together with the authorised CE representative. The resulting legal uncertainty, and its potential tension with the Brussels I Recast, has led the UPC Court of Appeal to refer a preliminary question to the Court of Justice of the European Union (Order of 6 March 2026, Dyson v Dreame), which will be pivotal in determining whether—and to what extent—the UPC's long-arm jurisdiction based on such an anchor defendant doctrine is subject to any meaningful boundaries.

Talk first, litigate later: the new MASC requirement, applicable also for (any?) patent dispute

At domestic level, the most relevant legislative development is procedural rather than substantive: the entry into force of Organic Law 1/2025 of 2 January, on measures to improve the efficiency of the Public Justice Service. This Law not only modifies the internal structure of the courts of first instance, but also introduces a mandatory requirement to engage in an alternative dispute resolution mechanism (commonly known by its Spanish acronym, “MASC”) prior to the commencement of any civil or commercial proceedings.

Compliance with a MASC constitutes an admissibility requirement for the claim and may take the form of mediation, direct negotiations or a confidential binding offer. Each of these mechanisms entails a minimum negotiation period, which can have a significant impact on litigation strategy. Only limited exceptions to this requirement apply, notably applications for preliminary injunctions filed prior to the action on the merits (which remain exceptional under Spanish law). As a general rule, therefore, patent litigation proceedings —both infringement and nullity proceedings — are also subject to the MASC requirement.

This has prompted debate as to whether MASCs should be mandatory in patent proceedings at all, given the limited —or even non‑existent— margin for negotiation in this type of dispute, particularly in nullity actions, which are public in nature, relate to public order and are, in principle, not subject to party disposition. While courts have generally accepted that patent invalidity raised by way of counterclaim should fall outside the MASC requirement, there is currently no uniform approach where nullity is brought as a main action. To date, only the Barcelona Commercial Courts have clarified that MASCs will not be required in patent invalidity actions (whether as a main action or counterclaim), nor in fact‑finding proceedings or the filing of protective letters, which are also specific proceedings in patent litigation. As regards other courts, these issues are expected to be resolved progressively through judicial practice.

Spanish courts and the EPO: aligned – but for how long in light of UPC caselaw?

From a substantive perspective, one of the most significant developments in 2025 was the apixaban case. In its landmark judgment of 24 April 2025, the Spanish Supreme Court addressed the issue of plausibility for the first time, expressly endorsing the approach set out by the Enlarged Board of Appeal (“EBA”) of the European Patent Office (“EPO”) in decision G 2/21. The Court adopted a standard closer to the “implausibility ab initio” approach, holding that plausibility should be assessed by determining whether, on the basis of the application as filed and the common general knowledge, the skilled person would have had any reason, at the filing date, to regard the alleged technical effect as implausible.

In the same case, and in the appeal judgment upheld by the Supreme Court, the Barcelona Court of Appeal dismissed a novelty attack based on an alleged lack of right to priority. The Court held that the attack relied on an overly formalistic and abusive invocation of the separate legal personality of two companies within the same corporate group, despite the absence of a formal written assignment of the priority right between them. This reasoning was aligned with the EBA decisions G1/22 and G2/22.

This alignment with the EPO doctrine is consistent with established Spanish practice, despite national courts not being formally bound by EPO case law. This trend is further illustrated by a recent judgment of the Barcelona Patent Court addressing lack of novelty due to prior use —an issue on which Spanish case law remains limited. In assessing public availability, the Court relied heavily on EPO practice, concluding that the installation of a prototype of the invention in a communal garage, without any access restrictions for the building’s residents and in the absence of confidentiality obligations, constituted novelty‑destroying prior use.

Looking ahead, the growing relevance of the UPC jurisprudence raises the question of whether Spanish courts will continue to follow EPO doctrine as closely. In particular, in the field of inventive step, where Spanish courts have traditionally applied the EPO’s problem–solution approach, it remains to be seen whether the holistic assessment recently endorsed by the UPC may exert influence over time. Similarly, in the area of infringement by equivalence, forthcoming guidance from the UPC Court of Appeal may offer an alternative to the Catnic–Improver test developed in the UK and traditionally applied by Spanish courts.

Trade secrets: better safe than sorry

Finally, a noticeable increase has been observed in trade secret litigation following misappropriation, prompting Spanish courts to further refine the criteria for determining when information qualifies for protection as a trade secret. In particular, in its judgment of 23 October 2025 and in line with Supreme Court case law, the Barcelona Court of Appeal held that claimants must (i) precisely identify the information allegedly protected —generic references to “know‑how” or to “valuable and sensitive information” being insufficient—and (ii) demonstrate the existence of specific and reasonable safeguarding measures, beyond standard and generic confidentiality clauses or basic security tools.

These decisions underline the importance for companies of acting diligently and adopting a comprehensive upfront strategy to protect their intangible assets, particularly given that trade secret breaches are not always immediately detectable and may cause irreversible harm if appropriate safeguards are not implemented in advance. When it comes to the protection of trade secrets, the well‑known Spanish proverb proves particularly apposite: prevention is better than cure.