The decision of the Court of Appeal in Yellow Sphere Innovations GmbH et al. v. Knaus Tabbert AG of 17th August 2026 (UPC-CoA_365/2025 and 367/2025)
Even more than three years after the UPCA came into force, numerous questions remain regarding the ‘patent package’. With the decision Yellow Sphere Innovations ./. Knaus Tabbert, the Court of Appeal has now largely clarified two of these issues, which concern alleged acts of infringement prior to the UPCA coming into force on 1st June 2023.
Knaus Tabbert was sued for patent infringement. The proceedings also involved acts of infringement alleged to have taken place in the period prior to 1st June 2023, i.e. before the UPCA came into force. Knaus Tabbert defended itself against these claims, arguing, amongst other things, that the UPC had no jurisdiction over claims based on acts of infringement that occurred before the UPCA came into force. The Court of Appeal therefore had to address the issue of the UPC’s jurisdiction in terms of time, as well as the question of the extent to which the UPCA is also applicable in substance.[1]
With regard to the first question, the Court of Appeal ruled that the UPC also had jurisdiction over claims based on acts of infringement committed prior to the entry into force of the UPCA. This did not infringe the prohibition on retroactive effect – neither under customary law nor under Article 28 of the Vienna Convention on the Law of Treaties (VCLT).[2] Whether the UPCA also applies in substance must be distinguished from the question of jurisdiction, and for reasons of legal certainty, the court must have the possibility of reviewing its jurisdiction without examining the merits of the case on the basis of the UPCA and the Brussels Ia Regulation (EUGVVO).[3]
This is not the first time that the Court of Appeal has dealt with the issue of ‘temporal jurisdiction’[4] . This decision, in turn, refers[5] to the case of XSYS v ESKO (judgement of 2nd June 2025, UPC_CoA_156/2025). XSYS was the defendant in the infringement proceedings and, by way of an objection under Rule 19 of the Rules of Procedure (RoP), challenged the UPC’s jurisdiction at first instance in respect of acts of use prior to 1st June 2023.[6] The Munich Local Chamber, which heard the case, established its jurisdiction in Order ORD_6487/2025, on the grounds that this was to be considered independently of the applicable law.[7] At the time, the Court of Appeal concurred with the view of the Munich Local Chamber that applicable law and jurisdiction are two aspects to be considered separately, and stated that the question of the UPC’s jurisdiction is governed by Article 32 of the UPCA and that the Local Chamber had applied this provision.[8] This was not a matter of retroactive effect and therefore did not constitute a breach of Article 28 of the VCLT.[9] The UPCA does not contain any limitation of jurisdiction to acts of infringement occurring within a specific period.[10] In particular, Articles 1 and 3 of the UPCA do not permit such a conclusion.[11]
The Court of Appeal did not consider it necessary to refer the matter to the ECJ, as even the interpretation most favourable to XSYS under Articles 28 and 31 of the VCLT would not lead to a different outcome.[12]
The Court of Appeal has now largely drawn upon the principles established in that case in its current decision.[13]
In line with this, the Court of Appeal held, in relation to the second question, that the UPC’s jurisdiction alone does not justify the application of the substantive law of the UPCA to the case in question. The fact that substantive provisions are also intended to apply to circumstances that had already arisen prior to their entry into force must be clearly apparent from the interpretation of the relevant provisions. The principle of the protection of legitimate expectations requires that one must be able to rely on a legal position that has been acquired once and for all. A different rule applies within the limits of retroactive effect, also having regard to Article 28 of the VCLT, where specific provisions on temporal application are enacted.[14]
The Court of Appeal found that the UPC does not contain any such provisions regarding temporal application to concluded cases, particularly not in Article 3 of the UPCA, which does not refer to applicability in the case of concluded cases.[15]
Nor does Article 24 of the UPCA contain such provisions. Rather, for cases concluded before 1 June 2023, national substantive law applies to European bundle patents pursuant to Article 24(2)(a) of the UPCA in conjunction with Article 8(1) of the Rome II Regulation.[16]
These findings therefore required a definition of the ‘concluded set of facts’ and a distinction to be drawn between the various types of claims arising from a patent infringement.
The Court of Appeal interprets the ‘concluded set of facts’ in paragraph 258 of the judgment as follows with regard to the claim for an injunction:
‘A concluded set of facts exists where a legal position has arisen. In the case of claims for an injunction, the set of facts is only concluded upon the final and genuine cessation of the infringement, because every threatened or actual infringement gives rise to a new claim for an injunction, which also has effect into the future.’[17]
With regard to injunctions, the Court of Appeal concluded that, should the conduct began before 1 June 2023 and the infringer did not end such conduct definitively and genuinely, the prohibition on retroactive effect does not preclude the applicability of the UPCA.[18] It remains unclear, however, what is meant by ‘definitive and genuine ending’. This requirement appears to a broader application of the UPCA than previous case law of Courts of first instance implied, according to which the key issue was “continuing infringement”, but which also held that an overly formalistic approach should not be adopted[19] . The Court of Appeal’s requirement for a definitive and serious ending of a condult could, for example, involve the submission of a cease-and-desist declaration subject to a penalty clause.
The same applies to remedial measures under Article 64(2)(b), (c), (d) and (e) of the UPCA[20]. The claims for recall and destruction from the distribution channels relate to the patent-infringing items still present in the distribution channels and thus do not concern any facts that were finalised before 1 June 2023. The same considerations apply to the claim for destruction.
The situation is different when it comes to claims for damages and related claims for information. In the case of damages, the termination of the individual act is decisive, as each individual act gives rise to a claim for damages. This also applies mutatis mutandis to claims for information where these implement Article 8 of the Enforcement Directive; by contrast, where claims for information are procedural in nature under national law, Article 67 of the UPCA applies.[21]
In the absence of a legal basis for a claim under the UPCA, national law is always applicable in respect of damages or compensation arising from the provisional protection of a published application.[22]
In the view of the Court of Appeal, it is for the parties to put forward their legal arguments and the opinions of private experts on national law. The burden of proof and presentation regarding national law lies with the party invoking a specific provision of national law[23] . However, in substantiating the claims asserted, it must not be overlooked that, under the Enforcement Directive, Member States are obliged to provide for certain legal consequences in their national law[24] . This gives rise to the presumption that the national provisions implementing the Enforcement Directive contain provisions corresponding to the UPCA and, in any event, do not deviate from them to the detriment of the patent proprietor. It is for the defendant to rebut this presumption[25] .
Whenever the term ‘retroactivity’ appears in the context of a decision, it catches the attention of those mindful of the rule of law. This is because, on the grounds of the protection of legitimate expectations, retroactivity is only permissible within certain limits.[26] The prohibition on retroactivity under EU law is derived from the principles of legal certainty and the protection of legitimate expectations.[27] With regard to treaties under international law, Article 28 of the VCLT stipulates that the provisions of a treaty shall not apply to acts performed or situations existing prior to the entry into force of the treaty, unless the treaty expressly provides otherwise.[28]
In his three-part essay[29], KLOPSCHINSKI examines the extent to which EU law and international law are relevant to the UPCA with regard to the treatment of retroactive effect. He concludes that the EU legal principles on retroactive effect apply where EU law is also implemented, for example in the implementation of the Enforcement Directive.[30] This is the case, he argues, in infringement proceedings.[31] The VCLT is applicable to the UPCA and, consequently, so is Article 28 of the VCLT, according to which it must be examined on a case-by-case basis whether an international treaty intends to have retroactive effect.[32] However, this cannot be inferred from the UPCA.[33] A key point raised by Klopschinski is the examination of the temporal scope of the concept of infringement, as Article 32(1)(a) of the UPCA governs jurisdiction over actions for actual or threatened infringement.[34] KIRCHER, on the other hand, points out that an action for infringement may also relate to acts committed prior to 1 June 2023.[35]
UPC case law takes a flexible approach to the temporal aspect[36] :
“The Court’s jurisdiction also covers acts of infringement committed prior to the entry into force of the UPC Agreement on 1st June 2023, provided that the European patent in question has not yet expired at that time.”[37]
“The Unified Patent Court has jurisdiction to rule on acts of infringement committed prior to the entry into force of the Agreement on a Unified Patent Court on 1st June 2023. This follows from Articles 3(c) and 32(1)(a) of the UPCA and the absence of any contrary intertemporal provisions.”[38]
“By referring to “actual or threatened infringements”, Art. 32 (1) (a) UPCA solely relates to the qualification of the infringing act as to be actual or merely threatened, but relates not to the point in time when such act took place.”[39]
“Jurisdiction and applicable law are distinct aspects that must be assessed separately. Neither can it be inferred from the UPC’s jurisdiction that the UPCA always applies to every set of facts submitted for a decision, nor is the applicable law decisive for the UPC’s jurisdiction.”[40]
For the time being, therefore, it should be noted that the Court of Appeal has continued its previous line of reasoning.[41] In any case, the UPCA is not without controversy, particularly in light of the Court of Appeal’s ruling in the case of Yellow Sphere GmbH v Knaus Tabbert AG.
[1] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 1 et seq.; para. 253 et seq.; Lower court: Düsseldorf Local Chamber, 10 April 2025, UPC_CFI_50/2024; see Baum/Wunderlich, GRUR Patent 2025, 615
[2] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 253
[3] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 254
[4] Term used, for example, by Klopschinski, GRUR Patent 2026, 7
[5] For example, Court of Appeal judgment of 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 253, 254
[6] Munich Regional Chamber, 10th February 2025, UPC_CFI_483/2024 (ORD_6487/2025), pp. 2, 3
[7] Court of Appeal, 2nd June 2025, UPC_CoA_156/2025 (APL_8790/2025), paras. 5, 6; Munich Local Chamber, 10th February 2025, UPC_CFI_483/2024 (ORD_6487/2025), p. 7 et seq.
[8] Court of Appeal, 2nd June 2025, UPC_CoA_156/2025 (APL_8790/2025), paras. 34, 36
[9] Court of Appeal, 2nd June 2025, UPC_CoA_156/2025 (APL_8790/2025), para. 36
[10] Court of Appeal, 2nd June 2025, UPC_CoA_156/2025 (APL_8790/2025), paras. 35, 36
[11] Court of Appeal, 2nd June 2025, UPC_CoA_156/2025 (APL_8790/2025), para. 26, 27
[12] Court of Appeal, 2nd June 2025, UPC_CoA_156/2025 (APL_8790/2025), para. 38
[13] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, see LS VIII and paras. 154, 156
[14] Entire paragraph, UPC Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, paras. 256, 257
[15] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 257; Kircher in Bopp/Kircher, HB Europäischer Patentprozess, 3rd ed. 2025, § 1, para. 18, regards Article 3 of the UPCA as at least a ‘point of reference for intertemporal applicability’
[16] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 257
[17] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 258
[18] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, paras. 259, 260
[19] Düsseldorf Local Chamber, 22nd June 2026, UPC_CFI_811/2024, paras. 73, 74
[20] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 260
[21] Entire paragraph, UPC Court of Appeal, 17 August 2026, UPC-CoA_365/2025 and 367/2025, paras. 261, 262
[22] UPC Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 263. The Court points out that there are also differing views which regard the UPCA as containing a general legal basis for damages or compensation, albeit without specifying this. However, Grabinski/Tilmann, in Tilmann/Plassmann, Einheitspatent, 1st ed. 2024, Art. 32 UPCA, para. 103, also see no substantive basis for this
[23] Court of Appeal judgment of 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 295
[24] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 297
[25] Court of Appeal, 17th August 2026, UPC-CoA_365/2025 and 367/2025, para. 297
[26] Dürig/Herzog/Grzeszick, 111th edition, June 2026, Art. 20 GG, paras. 72, 73
[27] Klopschinski, GRUR Patent 2026, 7, 10, para. 11 with further references
[28] Vienna Convention on the Law of Treaties, BGBl. 1985 II p. 926
[29] Klopschinski, GRUR Patent 2026, 7; GRUR Patent 2026, 74; GRUR Patent 2026, 138
[30] Klopschinski, GRUR Patent 2026, 7, 11, para. 17
[31] Klopschinski, GRUR Patent 2026, 7, 11, para. 17; p. 17, para. 36
[32] Klopschinski, GRUR Patent 2026, 7, 14, 15, para. 26
[33] Klopschinski, GRUR Patent 2026, 7, 18, para. 37
[34] Klopschinski, GRUR Patent 2026, 74, 78, from para. 21. Klopschinski also distinguishes here according to the type of patent (EPeW/EP)
[35] Kircher in Bopp/Kircher, HB Europäischer Patentprozess, §13, para. 3, footnote 2
[36] The following list is provided in lieu of many others. A list of the relevant decisions can be found in Klopschinski, GRUR Patent 2026, 7, 9, para. 8
[37] Court of Appeal judgment of 16th January 2025, UPC_CoA_30/2024 (APL_4000/2024), para. 2 (Fives v. REEL)
[38] Munich Local Chamber, 29th September 2023, UPC_CFI_15/2023 (ORD_576853/2023), p. 10 (Edwards Lifescience v. Meril)
[39] Mannheim Local Chamber, 4th April 2025, UPC_CFI_750/2025 (ORD_11176/2025), p. 6 (Fingon v Samsung Electronics)
[40] Munich Local Chamber, 10th February 2025, UPC_CFI_342/2024 (ORD_26161/2025), para. 2 (Phoenix v. ILME)
[41] Schumacher/Eker note in GRUR Patent 2025, 574, 576, with regard to the XSYS v ESKO case, that the decision came as little surprise and that it would thereby reduce legal uncertainty.
