UPC’s First Judgment – Private International Law Remarks

Since 2023, the Unified Patent Court (UPC) has served as a supranational patent litigation forum for 18 EU member states. On 3 October 2025 the UPC Court of Appeal delivered its first final judgment, in a dispute between Philips and Belkin concerning alleged infringement of a patent relating to wireless charging technology.

Although the UPC primarily applies the Agreement on the Unified Patent Court (UPCA), which constitutes a uniform set of rules for all contracting states, the judgment is also noteworthy also from a private international law perspective.

Specifically, there are two aspects of the judgment that are interesting from a private international law perspective. First, the court explicitly relied on the Brussels I bis Regulation to assess the res judicata effect of a prior German judgment to the dispute. Second, the UPC’s approach to filling gaps in the UPCA through uniform interpretation raises broader questions about the relationship between the UPCA and differing substantive law regimes of the member states, particularly in areas such as company law and employment law, as well as its interaction with EU choice-of-law instruments.

Summary

Philips initiated proceedings in Munich Local Division (Court of first instance of the UPC) for alleged patent infringement under the UPCA against Belkin and its managing directors. The court of first instance held that the managers were partly liable, but all parties involved appealed the decision to the UPC Court of Appeal.

Overturning the court of first instance’s judgment, the Court of Appeal found the managing directors not liable for patent infringement. Still, the Court of Appeal held that managing directors can be held liable on grounds of the UPCA. This obiter dictum conclusion seems to be reached regardless of the law applicable to the managing director’s employment contract or to the law applicable to the company which he or she directs.

Res judicata Effect of a Judgment from an EU Member State

In 2019, Philips had filed a lawsuit against Belkin for issues related to the patent in question for the UPC. That lawsuit was filed in a national German court that held that Belkin was not infringing Philip’s patent. For the UPC, Belkin argued that not only the operative part of the German judgment (i.e. the conclusions) should be binding under Article 36 of the Brussels I bis Regulation, but that also the arguments leading the court there should have res judicata effect for the UPC. Article 36 prescribes that a judgment from a member state shall be recognised in all other EU member states. Belkin’s procedural argument put this recognition mechanism in Brussels I to the test in a new context. First, it is not immediately apparent how the Brussels I bis Regulation is to work in relation to the UPC. Second, the issue of how to determine the res judicata effect of a foreign decision is also not self-evident. Shall it follow the law in the country where the decision was rendered, the country where it is to be recognised or shall it be autonomously determined?

As regards the application of the Brussels I bis Regulation in relation to the UPC, it can first be noted that the UPC works as a national court for the 18 contracting EU Member States. Hence, Chapter VI of the UPCA dealing with issues of international jurisdiction explicitly refers to the Brussels I bis Regulation and the 2007 Lugano Convention for determining the court’s international jurisdiction (Article 31 UPCA). Also, it follows from Article 34 of the UPCA that a UPC decision has legal effect in all contracting states where the European patent is valid. In other words, there is no need to recognise and enforce a UPC judgment in a UPCA contracting state.

In the present case, the recognition issue arose in the opposite direction from what is governed in Article 34 of the UPCA. A judgment from a UPCA contracting state (Germany) was to be recognised by the UPC. A somewhat peculiar circumstance is that the seat of the UPC is also located in Germany. Despite that both courts are located in Germany, the relation between the courts must go the way over EU private international law.

Being a (supra-)national court for the 18 contracting member states, one can regard the UPCA system as a separate jurisdiction in this manner. Even though the claimant’s option to initiate patent proceedings before the national courts in a UPCA contracting state is only available during a transition period, that period is lengthy. Similar situations may therefore arise for a considerable time. Moreover, the same issue of recognition will become relevant for judgments from EU Member States that are not contracting parties to the UPCA as well as in relation to the Lugano Convention States.

As regards how to determine the res judicata effect of a foreign decision, Belkin had argued that it follows from Gothaer Allgemeine Versicherung, C-456/11, EU:C:2012:719, that the recognition mechanism requires that not only the conclusion of a decision, but also the grounds for it shall be recognized. Here, the UPC made the remark that Gothaer Allgemeine Versicherung concerned the special situation when a foreign court has decided on the validity of a forum selection clause. Such a clause cannot be contested in more than one other country than the country chosen in the forum selection clause.

Instead, for determining the res judicata effect of a decision, the Brussels I bis Regulation relies on a conflict of laws inspired solution favouring the law in the country where the judgment was rendered. This idea was presented already in the 1979 Jenard Report and was last confirmed by the CJEU in BNP Paribas, C-567/21, EU:C:2023:452 (reported for this blog here). With references to the two judgments above, the UPC held in its judgment that the res judicata effect of the German judgment should be governed by German law.

Analyzing German civil procedural law the UPC held that only the operative part of the judgment is legally binding and has res judicata effect. Hence, Belkin’s res judicata argument had only effect for the German patents and for those companies in the dispute that had also been parties in the German national procedure.

UPC’s Method of Filling Gaps

Apart from the obvious EU private international law aspect of the UPC’s judgment in its application of the Brussels I bis Regulation, also the substantive law interpretation methodology in the judgment deserves some attention. As was mentioned above the UPC found that a managing director may be held liable for patent infringements that he or she ought to have had knowledge of, even if no such liability was imposed in the case at hand. Here, it is noticeable that the UPCA contains no explicit rules for holding a managing director or an employee liable. Nor has this been harmonized in the EU or among the contracting UPCA states. Given the substantive law diversity among the different states, one could think that issues not explicitly covered by the UPCA would be subject to private international law considerations.

That private international law should play a role in disputes for the UPC follows from Article 24 of the UPCA. This Article first sets out the sources of law on which the UPC shall base its decisions (EU law, the Agreement itself, international patent conventions and national law). Although national law appears at the bottom of the list, Article 24(2) expressly instructs the Court to determine the applicable national law through private international law rules.

Albeit, the explicit reference to private international law and the role for substantive national law, the UPC does not bother to take such a detour over conflict of law rules. Instead, the Court cuts straight to the chase and creates an autonomous personal liability mechanism in paragraphs 189–200 of the judgment.

Even if the court does not apply private international law rules, substantive national law plays a significant role in the creation of the personal liability mechanism for managing directors. With inspiration from German, Dutch and French case law, the UPC holds that personal liability for a managing director must be a possibility also under the UPCA.

Undeniably, taking the hard harmonization path that the UPC does has its advantages. Not least for the efficiency of the UPCA. Still, such a hard harmonization does not really take into consideration the various substantive law solutions for company law liability and employment law that managing directors probably try to comply with.

If one glances at how the issue would have been resolved under the Rome II Regulation containing rules on the law applicable for non-contractual obligations, there is the conflict of law rule for intellectual property rights in article 8 pointing out the law in the country where protection is sought. If one can count the UPCA regime as a “country” that would certainly speak in favour of the UPC’s conclusions and methodology for filling gaps. Also, it follows from Article 15 of the Rome II Regulation that “the determination of persons who may be held liable for acts performed by them” is an issue subject to the scope of the law applicable. However, it is a fact that substantive law in the EU differs when it comes to these issues. Also, when it comes to personal liability for directors of a company, the company law exception in Article 1 p. 2(d) of the Rome II Regulation could come into question.

In the pending CJEU case Wunner, C-77/24 the question whether personal liability is subject to the Rome II Regulation or out of its scope will probably be assessed. Just like in the UPC case, non-contractual liability for managing directors has been sought. In the opinion of advocate general Emiliou (Wunner), it is argued that such personal liability is not part of the exception, but part of the Rome II Regulation.

Comment

UPC’s first judgment makes it clear that the UPCA is a new creature in EU law. This is particularly shown in the UPC’s method for filling gaps. Unlike how gaps in EU regulation are filled with the applicable national law, UPC leaves little room for national substantive law differences. Also compared to most other substantive supranational legal frameworks like conventions, UPCA differs by having a uniform supreme court (the UPC). Still, future interactions between UPCA and private international law will quiet clearly arise regardless of the fact that the UPC seems not to resort to private international law without necessity.

Having reflected on the judgment, I cannot refrain from making a side remark about its language and formal structure. As for language, the judgment is in German. That in itself is not a problem. The problem is that no English translation has been made available, even though seven weeks have passed since the judgment was rendered. Today, it is safe to assume that anyone interested in EU law understands English, whereas the same cannot, whether one likes it or not, be said of German (or any other language). Notably, the UPC local courts in Germany, France and Italy allowed for the usage of English as late as when the UPC opened (see this press release of 1 June 2023). If the UPC wants to position itself  as a “player” in European law, it must improve its accessibility. The simplest way of doing so is to make sure that all precedent judgments are available in English. Preferably on the same day as the judgment is issued in its original language.

Another point relating to accessibility and readability is that the UPC has chosen an internationally unusual method of structuring its judgment. Instead of building arguments from the bottom up (like the Court of Justice of the EU and the European Court of Human Rights do), the UPC starts with its conclusions and explain them backwards. This method probably has advantages, but it makes the line of reasoning difficult to follow, at least in my view.