Multijurisdictional patent disputes have increasingly featured litigation filed both in national courts and before Europe’s Unified Patent Court (UPC), where plaintiffs can seek damages and injunctive relief spanning 18 participating EU countries. Since the UPC allows similarly sweeping revocation claims, some patent owners have chosen to opt certain patents out of the court’s jurisdiction to protect key assets from invalidation. While UPC rules allow patent owners to withdraw opt-outs under certain circumstances, they cannot do so after filing national litigation over those assets. Early caselaw interpreted this prohibition more broadly, to include cases filed in national courts before the UPC’s June 2023 launch. However, the Court of Appeal has now held otherwise—ruling that UPC rules do not bar the withdrawal of an opt-out when the national litigation in question was filed before the court began its operations.