The introduction of the unitary patent and the Unified Patent Court (UPC) has raised the question of the appropriate forum for patent litigation once again. In Germany, as in other contracting states, rights holders were long limited to bringing actions before national courts. The UPC now provides a centralized, supranational forum for the judicial enforcement of patent rights.
Key Question and Background
One of the central issues in this context concerns the temporal scope of the UPC’s jurisdiction:
Does the UPC’s jurisdiction apply only to patent infringements committed after the Agreement on a Unified Patent Court (UPCA) entered into force on June 1, 2023? What about infringements that occurred during an opt-out period?
Article 32(1) UPCA regulates the subject-matter jurisdiction of the UPC but does not contain any temporal limitation.
At the same time, under Article 83 UPCA, national courts retain parallel jurisdiction during a seven-year transitional period following the UPCA’s entry into force. During this period, patent holders have the option to opt their European patents out of the jurisdiction of the UPC. If the opt-out is later withdrawn, the patent re-enters the exclusive jurisdiction of the UPC.
Decision of the Court of Appeal
The order of the Court of Appeal of June 2, 2025 in XSYS v. ESKO (UPC CoA 156/2025) provides guidance and has significant practical implications.
The background to the decision concerns a European patent for which the proprietor had initially declared an opt-out and later withdrew it. After the patent proprietor brought an action before the Munich Local Division of the UPC, the defendant challenged the UPC’s jurisdiction over acts of infringement that had occurred either before June 1, 2023 or during the opt-out period.
The Court of Appeal rejected the notion of a fragmented jurisdiction of the UPC. According to the ruling, the jurisdiction of the Unified Patent Court also extends to acts of patent infringement committed before the UPCA entered into force, provided that the patent is subject to the jurisdiction of the UPC. In addition, the court held that an effective withdrawal from an opt-out brings the patent fully back under the jurisdiction of the Unified Patent Court – both for future acts of infringement and for those committed during the period in which the opt-out was in effect.
In the court’s view, Article 32(1) UPCA establishes the exclusive jurisdiction of the Unified Patent Court for patent infringement actions without any temporal limitation. Both the wording of the provision and the purpose of the Agreement – the establishment of a unified patent court to overcome the fragmentation of the European patent system and the divergences between national jurisdictions – argue against any temporal restriction.
During the seven-year transitional period under Article 83 UPCA, the Unified Patent Court and national courts share parallel jurisdiction over European patents, provided the patent has not been opted out of the UPC’s exclusive jurisdiction under Article 83(3) UPCA. In this context, the patent proprietor has the choice of whether to bring an infringement action before the UPC or before a national court. However, this choice merely concerns the selection of the forum and does not result in any temporal limitation of the jurisdiction of the chosen court.
Accordingly, the withdrawal of an opt-out pursuant to Art. 83(4) UPCA also results in the patent once again falling fully under the exclusive jurisdiction of the UPC. In this case, the UPC’s jurisdiction also extends to infringements committed during the period in which the opt-out was in effect.
The question of the applicable substantive law for acts committed before the entry into force of the UPCA remains unresolved. The court has reserved the decision on this issue for a later stage of the proceedings.
Conclusion
The decision confirms the UPC as a supranational forum for patent enforcement and provides clarity on the temporal scope of its jurisdiction.
In practical terms, this enables patent holders to bring claims for both recent and earlier acts of infringement – including those committed before the UPCA entered into force – within a single proceeding. Opt-out strategies therefore need to be adjusted accordingly, and market participants should be aware of the risk of retroactive claims.
The question of which substantive law applies to acts committed before the UPCA entered into force remains open.
