European patent litigation strategy: choosing the forum

During the transitional period provided for by Article 83 of the Agreement on a Unified Patent Court, a European patent can be enforced before the UPC or before the national courts. A proprietor who has opted the patent out of the UPC’s jurisdiction can only sue before the national courts. A European patent with unitary effect falls within the exclusive jurisdiction of the UPC.

The difference in reach is decisive. A UPC decision takes effect in all participating States where the patent is in force (Article 34 of the Agreement). A national decision is limited to the State whose court gave it.

Alongside these two routes sits opposition before the European Patent Office, open to any third party within nine months of grant (Article 99 EPC). It is handled by patent attorneys, with whom we coordinate the overall strategy.

Before the UPC local divisions, an infringement action is decided on the merits in a median of 16.8 months. The Paris local division is the fastest of the ranked divisions (13.8 months, on three decisions), Düsseldorf the slowest (17.9 months). These figures, compiled by the Lab up to September 2026, describe the decisions handed down. They exclude pending cases, which are often the longest.

Before national courts, the timetable depends on the chamber seised and on how validity is handled. In Paris, infringement and validity are decided together by the same specialised panel. Elsewhere, as in Germany, they fall to separate courts, which changes the pace and the balance of the case.

The forum is often chosen from the evidence. In France, the saisie-contrefaçon (Article L. 615-5 of the French Intellectual Property Code) allows infringement to be recorded at the alleged infringer’s premises, without prior notice. The UPC has adopted this model with the saisie under Article 60 of the Agreement, which we describe on our page on evidence before the UPC.

The Lab shows that a saisie before the UPC is almost always granted and usually survives a review requested by the defendant: of 13 saisies reviewed, 9 were upheld unchanged. All three saisies reviewed by the Paris local division were upheld.

Of the 43 UPC decisions ruling on validity, 36 leave the patent standing, as granted or in amended form, and 7 revoke it in full. Infringement is found in 23 of the 43 decisions ruling on it. At the Paris seat of the central division, all four patents decided on the merits were maintained in amended form.

Appeals are taking a growing share: the UPC Court of Appeal has issued 493 decisions and orders in 308 proceedings. The detail by division and by issue is available in the UPC statistics.

A single action before the UPC can lead to an injunction in every participating State where the patent is in force. That leverage carries weight in a negotiation. It comes at a price: the defendant can counterclaim for revocation, and a revocation by the UPC applies in all those States at once.

For a portfolio whose value rests on a few titles, the opt-out remains a protective tool. It can be withdrawn, unless an action has already been brought before a national court (Article 83(4) of the Agreement). The choice is made title by title, with the patent attorney, as explained on our UPC page.

To attack an opponent’s patent, a standalone revocation action is brought before the central division. Its Paris seat is the leading venue: 57 cases identified by the Lab, more than the Munich and Milan sections combined.

The major national courts remain options, each with its own logic. We set out their general features here, without claiming to analyse foreign law.

Germany. Infringement is heard by the regional courts, notably Düsseldorf, Munich and Mannheim, while validity is decided by the Federal Patent Court. This separation can lead to an injunction before the validity of the patent has been decided.

The Netherlands. The District Court of The Hague has exclusive jurisdiction over patents. It hears cases on the merits under an accelerated procedure and grants preliminary relief where urgency justifies it.

Italy. Patent litigation belongs to the specialised business sections of the courts, Milan first among them. The technical expert appointed by the court plays a central role, and the descrizione offers a means of evidence close to the saisie-contrefaçon.

All three States also participate in the UPC, which has local divisions there. Any action abroad is conducted with local counsel, whom we select and coordinate.

The same patent can be argued at the same time before the UPC, a national court and the EPO. The lis pendens rules of the Brussels I bis Regulation (Articles 29 and 71c) require the court second seised to stay its proceedings where the parties and the cause of action are the same. Where an opposition is pending, the UPC may stay its proceedings but is not bound to (Article 33(10) of the Agreement).

These rules interact with the languages of proceedings, opposition deadlines and the client’s commercial timetable. We build them into a single calendar from the outset, so that no proceeding weakens another.

For standard essential patents, the choice of forum is read in light of the licensing negotiation. The framework set by the Court of Justice in Huawei v ZTE (16 July 2015, C-170/13) applies before every court in the Union, but each applies it with its own method. The FRAND Litigation Watch follows these decisions.

In the life sciences, the stakes often centre on preliminary measures and the launch of a generic or biosimilar. Supplementary protection certificates based on a European patent also fall within the UPC’s jurisdiction, unless opted out. The Pharma Litigation Watch follows this litigation.