Key takeaways
The Court of Appeal may authorize oral hearings in a language other than the language of proceedings, without formally changing the language of the case, based on considerations of pragmatism and procedural efficiency
The appellants’ representative understood French but lacked sufficient oral proficiency for optimal representation. The Court permitted both parties to plead in English at the hearing of 26 May 2026, while French remained the language of proceedings. The possibility of hiring an interpreter under R. 109.4 RoP was considered but deemed less effective than direct oral advocacy in English.
The consent of the opposing party significantly strengthens a request to change the language of oral hearings, and may render subsidiary requests moot
The respondent (Valeo) agreed with the appellants’ primary request to hold the hearing entirely in English and asked the Court to order exactly that. Since both parties were aligned, the Court granted the primary request and found it unnecessary to rule on the subsidiary request (allowing only the appellants’ representative to plead in English while the hearing otherwise remained in French).
The Preamble of the RoP (paras. 4 and 5) serves as a substantive legal basis for judicial discretion on procedural organization, requiring flexibility, efficiency and fairness
The Court relied on the principle that procedural rules must be applied in a “flexible and balanced manner” to organize proceedings “in the most efficient and cost-effective way” (RoP, Preamble, para. 4), and that justice and equity require consideration of all parties’ legitimate interests (RoP, Preamble, para. 5). These principles were treated as the primary legal foundation for the order.
The Court of Appeal relies on its own prior practice between the same parties as persuasive precedent for procedural decisions
The Court expressly referred to its own procedural order of 3 April 2026 in joined cases UPC_CoA_004/2026 and UPC_CoA_013/2026, involving the same parties (Robert Bosch v Valeo), where the hearing had likewise been conducted in English. This prior decision was cited as a factor justifying the same outcome in the present case.
Decisions on preliminary objections under R. 19 RoP follow a multi-step review mechanism: Judge-Rapporteur order, panel review, and appeal with leave
The defendants raised a preliminary objection under R. 19 RoP before the Paris Local Division challenging jurisdiction and the language of proceedings. The Judge-Rapporteur rejected it (order of 17 February 2026). The panel confirmed the rejection on review but granted leave to appeal (order of 23 March 2026), enabling the defendants to bring the matter before the Court of Appeal (UPC_CoA_50/2026).
Division
Court of Appeal, Luxembourg
UPC number
UPC_CoA_50/2026
Type of proceedings
Appeal proceedings (procedural order on language of oral hearing)
Parties
Appellants: Robert Bosch Doo Beograd; Robert Bosch France SAS; Robert Bosch GmbH; Robert Bosch S.A; Robert Bosch Produktie S.A; Bosch Automotive Products (Changsha) Co., Ltd.
Respondent: Valeo Systèmes d’Essuyage
Patent(s)
EP 4 144 599
Jurisdictions
UPC
Body of legislation / Rules
R. 19 RoP, R. 109.4 RoP, RoP Preamble paras. 4 and 5

