When does the UPC switch languages?

Lessons from five language‑change orders (2024‑2025)

Since the Unified Patent Court (UPC) opened its doors in June 2023, parties have quickly tested Article 49 (5) UPCA and Rule 323 RoP, asking the Court to switch from a local language to the language of the patent — almost always English. Five select orders from the Court of First Instance from the past year illustrate what will, and what will not, tip the scale.

This sample is small but diverse: two applications by Big Tech defendants (Ona Patents SL v. Apple, UPC_CFI_99/2024, and Ona Patents SL v. Google, UPC_CFI_100/2024) were refused and the appeal thrown out, due to closure of the written procedure; two requests in multinational supply‑chain disputes (Maxeon v. Aiko, UPC_CFI_336/2024, and InterDigital v. Disney, UPC_CFI_292/2025) were granted; and one medical‑device fight (MED‑EL v. Advanced Bionics, UPC_CFI_410/2023) ended in a refusal. All five were decided by President of the Court of First Instance, Florence Butin, as set forth by Art. 49 (5) UPCA, ensuring doctrinal consistency while revealing how finely the balancing exercise is calibrated.

1. Factors that consistently move the Court

• Language of the patent and prior art
The Court starts from the text of Article 49 (5) UPCA: using the grant language promotes technical accuracy. In every granted order the patent itself and most exhibits were already in English, so switching avoided duplication and mistranslation.

• Working language of both sides
Where claimant and defendant already negotiate, draft and contract in English, the Court sees little fairness in forcing one party to defend itself in German. This was evident in InterDigital v. Disney and Maxeon v. Aiko, where all corporate decision‑makers operated in English.

• Cross‑border coordination needs
Multi‑defendant cases spanning several EU states persuade the Court that a single “neutral” procedural language reduces cost and delay. The Mannheim order in InterDigital v. Disney underlined the logistical burden for the defendant (Disney) of translating pleadings for ten U.S. and Dutch entities.

• Dead‑heat → defendant wins
Echoing the Court of Appeal in 10x Genomics v. Curio (UPC_CoA_101/2024, ApL_12116/2024), President Butin treats the defendant’s preference as decisive when the overall balance of interests is otherwise even, referring to Art. 49 (5) UPCA, which states that the President of the Court of First Instance decides “on grounds of fairness and taking into account all relevant circumstances, including the position of parties, in particular the position of the defendant”. This tie‑breaker tipped the scale in Maxeon v. Aiko, even warranting a headnote (No. 2) to this order.

2. Arguments that rarely persuade

• “We are a global giant, so English is easier.”
Apple and Google invoked the lingua franca of their headquarters, but the Court refused to magnify an already dominant party’s convenience at the expense of a start‑up claimant that had prepared its German case months in advance.

• Parallel proceedings chosen by the applicant
Advanced Bionics relied on a pending English‑language revocation action it had itself filed in Paris. The Court called that a strategic choice and refused to let it dictate the language of infringement proceedings in Mannheim, as keeping German is “not obviously affecting the conditions under which the defence is exercised in the present action”.

• Presence of English‑speaking lawyers
The Court repeatedly stressed that counsel’s language skills cannot cure the disadvantage faced by the client’s internal teams or senior management (for instance in the 2nd headnote to Maxeon v. Aiko).

• Generic cost‑savings claims
Parties must show concrete prejudice, not just “translation costs.” Without evidence of real delay or risk, the Court treats such costs as the ordinary price of litigation.

3. Issues weighed differently across the five orders

• Relative size and resources
When the claimant was a scale‑up (Ona Patents) and the defendant a blue‑chip behemoth (Google and Apple respectively), the Court emphasised the power imbalance and kept German as the forum language. In Maxeon v. Aiko, by contrast, two multinationals of comparable heft neutralised this factor.

• Location of defendants
The presence of several German entities did not block a switch in Maxeon v. Aiko — because key technical staff sat in China and communication ran in English. Yet in MED‑EL v. Advanced Bionics, two German‑speaking defendants were enough to keep German as the language of proceedings.

• Timing and formality
All five orders confirm that an application filed even before the Statement of Defence, or through the CMS ‘generic application’ channel, is procedurally admissible. Nevertheless, Apple and Google were criticised for waiting until ten weeks after service, feeding the perception of tactical delay.

• Management‑level comprehension
The Düsseldorf order in Maxeon v. Aiko (2nd headnote) gave weight to the fact that none of the Aiko group’s senior legal managers spoke German, whereas Maxeon’s chief legal officer was an English speaker (echoing the CofA in 10x Genomics v. Curio once again). The Mannheim order in MED‑EL v. Advanced Bionics found no comparable mismatch and so discounted the point.

4. Practical checklist for future applicants

✔ File early — ideally with or shortly after your appearance — and explain why refraining from a language change will hamper your defence under the tight UPC calendar.

✔ Prove that decision‑makers on both sides already operate in English or another suitable language.

✔ Show that exhibits, prior art and parallel EPO or national files are predominantly in English or another suitable language.

✖ Don’t rely on your own size, your counsel’s fluency, or proceedings you chose to start elsewhere.

5. Take‑away

While dominant, English has no automatic primacy at the UPC. A request under Rule 323 succeeds only when it serves fairness, measured case‑by‑case: does the existing language place a meaningful burden on the applicant, and will the switch harm the other side? If the balance is even, the defendant gets the benefit. Until that calculus changes, litigants should prepare their narratives — and their evidence — accordingly.