Forum shopping before the UPC: the map, the language and Article 33

The Unified Patent Court was meant to end the fragmentation of European patent litigation. Three years after it opened, the picture is more subtle: beneath a single text, the Court offers a structured menu of procedural options, and the choice of division, language and timing has become a central parameter of any strategy. Forum shopping has not disappeared, it has moved inside the system.

That shift is not a malfunction. The architecture of theAgreement on a Unified Patent Court (UPCA) itself organises plurality: a dozen local divisions, a Nordic-Baltic regional division, a central division split between Paris, Munich and Milan, and internal competence rules that leave claimants genuine room for choice. Reading that map is understanding where cases are prepared, and sometimes where they are won.

One text, several forums

TheArticle 33 UPCA . For infringement actions, the claimant may seise the division of the place of infringement or that of the defendant's domicile. Where infringement occurs across several territories, the ordinary situation for products distributed Europe-wide, the option is real: several divisions have concurrent competence, and the choice belongs to whoever moves first.

The Court of Appeal has just widened that set of options. In Valeo v Bosch (orders of 22 June 2026, UPC_CoA_4/2026 and UPC_CoA_13/2026), it held that the third limb of Article 33(1) UPCA provides an autonomous basis of competence: where at least one co-defendant has no connection to any local or regional division, the central division may hear the action against all commercially related defendants sued for the same infringement. For litigation against international groups, the central division has thus become a genuine gateway in its own right.

This pluralism is not neutral. Despite the formal unity of the applicable law, each division works with its own tempo, its default language, its evidentiary habits and the legacy of its national judicial culture. UPC strategy therefore begins well before the merits: it begins with geography.

Opt-out as a tactical gateway

TheArticle 83(3) UPCAhas become a lever. Theopt-out allows a proprietor to remove its classical European patent from the Court's jurisdiction; its withdrawal, at a time of the proprietor's choosing, allows a return. Between the two lies a game of anticipation: locking the title away before a competitor files a central revocation action (Article 65 UPCA), or re-entering the system at the moment chosen for the offensive.

The practical consequence is clear: opt-out decisions are not taken patent by patent, in the abstract, but portfolio by portfolio, in light of the litigation scenarios one wishes to open or close. A poorly calibrated opt-out can deprive the proprietor of the very forum it would have wanted to use.

What the map of divisions reveals

The first years of practice draw fairly legible preferences, which owe less to the text than to the traditions each division inherits:

• For evidence preservation (Article 60 UPCA), the French and Italian divisions attract applicants: the judges' familiarity with the French saisie-contrefaçon (Article L. 615-5 of the French Intellectual Property Code) can be read in C-Kore (Paris local division) and Oerlikon (Milan local division).
• The Hague division approaches intrusive measures with the caution inherited from Dutch law: seized materials are placed under seal and their examination deferred to subsequent expert review, the reverse of French practice.
• For provisional measures (Article 62 UPCA), the German divisions benefit from a long tradition of preliminary protection in industrial property, illustrated as early as September 2023 by the 10x Genomics v NanoString injunction of the Munich local division.

Potential defendants must read this map in mirror image: a party fearing an ex parte measure before a division reputed to be receptive is well advised to file a protective letter, and to prepare its defence to a preliminary injunction before any writ is served.

Language and tempo

The language of proceedings is the other variable of choice. The possibility of conducting the case in English, the language of grant of most European patents, has reshuffled the deck: English has established itself as the dominant language of proceedings, and the Court of Appeal has framed language-change requests in a manner favourable to non-German-speaking parties.

The centre of gravity of the litigation reflects this. The German divisions, overwhelmingly dominant in the early months, accounted for only around half of new infringement actions by spring 2026, to the benefit in particular of Paris, Milan and The Hague. The reflex of filing everything in Munich is no longer a strategy: it is a habit, and habits carry a price.

Plurality without coordination

The system's weak point is not plurality but the lack of tooling to manage it. Article 33(2) UPCA borrows the lis pendens logic of the Brussels I bis Regulation, yet no alert mechanism signals parallel actions to the divisions: no systematic disclosure obligation, no interoperable register between divisions or with national courts. Each party reconstructs the state of multi-jurisdictional patent litigation by its own means, notably through the Court's database of decisions and orders.

A manageable complexity would require real-time signalling of related proceedings, a centralised register and a coordinating interpretative body. In the meantime, coherence will come less from textual uniformity than from the strategic transparency of the players, and the Court already defends its own perimeter, as the rise of anti-anti-suit injunctionsshows. After two years of case law, one thing is settled: internal forum shopping is not an anomaly to be corrected, it is a given to be mastered.

Key takeaways

• Forum shopping now operates inside the UPC: choice of division, language and timing, on the basis of Article 33 UPCA.
• Since Valeo v Bosch (CoA, 22 June 2026), the central division offers an autonomous basis of competence for actions against co-defendants where one has no local or regional connection.
• The Article 83(3) UPCA opt-out is managed as a tactical lever, portfolio by portfolio, not as an administrative formality.
• The French and Italian divisions dominate evidence preservation, the German divisions provisional measures, The Hague favours the protection of secrets.
• English has become the dominant language and the relative weight of the German divisions is receding: the 2026 map is no longer that of 2023.
• No mechanism coordinates parallel actions between divisions: procedural monitoring falls to the parties.

Frequently asked questions

Can you freely choose your division before the UPC?

Within the limits of Article 33 UPCA: an infringement action may be brought before the division of the place of infringement or that of the defendant's domicile. For acts committed in several participating states, several divisions have competence and the claimant chooses; the central division is added in certain multi-defendant configurations.

Is the opt-out still useful in 2026?

Yes, during the transitional period. It shields a classical European patent from a centralised revocation action, but also deprives its proprietor of the unified forum. The decision is taken in light of the portfolio's litigation scenarios, and its withdrawal must be anticipated before any action is filed.

Can you obtain proceedings in English?

Very often. Most divisions have added English to their languages of proceedings, and a switch to the language of grant of the patent can be requested during the case, the Court of Appeal having clarified the assessment criteria in a manner favourable to parties whose working language is English.

How does the UPC handle parallel actions between divisions?

Article 33(2) UPCA organises internal lis pendens, but no automatic alert system exists between divisions. Detecting related proceedings rests on the parties' vigilance, which makes litigation monitoring a fully fledged element of strategy.

Dhenne Avocats builds forum strategies before the Unified Patent Court : choice of division and language, opt-out management, coordination of parallel actions, for proprietors and defendants alike. Talk to us.

This article is an original and substantially updated adaptation of an analysis by Matthieu Dhenne first published on Kluwer Patent Blog on July 18, 2025: The Coded Procedural Landscape: Forum Shopping Inside the UPC Matrix.