On 17 April 2024, the Court of Appeal of the UPC handed down its decision concerning the language of proceedings in the (undoubtedly ground-breaking) case of Curio Bioscience v 10x Genomics. Curio had applied in January to have the language of proceedings changed from German to English, but their application was rejected in February at first instance by the Düsseldorf Local Division.

The Court of Appeal overruled the first-instance court, holding that it had not taken into account all relevant circumstances under Article 49(5) UPCA. Presiding Judge Rian Kalden, together with legally qualified judges, Ingeborg Simonsson and Patricia Rombach, held that relevant circumstances could include:

  • The language mostly used in the field of technology involved, particularly the language in which the evidence (including the prior art) is written;
  • The nationality or domicile of the parties;
  • The relative size of the parties and their resources to deal with international disputes; and
  • The effect of a change of language on the course of the proceedings, including possible delays.

However, the nationalities and language skills of the representatives before the court and the judges hearing a case were held not to be generally relevant circumstances.

In this case, the Court of Appeal gave considerable weight to the facts that both parties were US companies, and that the language of the underlying technology was English, as was almost all of the evidence relied on by the parties. The Court also accepted Curio’s submission that, as it is a much smaller company than 10x Genomics, it would suffer a heavier burden from the language of the proceedings being different from the company language. The Court did not, however, attach much weight to 10x Genomics’ reliance on the fact that 20% of EU citizens would speak German as a native language and 10% as a foreign language, as it did not relate either to the dispute or to the parties.

The criteria relied on by the Court of Appeal suggest that English may continue to become more prominent as a language of proceedings at the UPC. As of the time of publication, the proportion of all cases in English is on par with German and the trend has shown English increasing rapidly. The high proportion of proceedings in German may be due to the fact that the German Local Divisions did not confirm that English language proceedings would be acceptable until the UPC start date.  However, even within German local divisions the use of English as the language of the proceedings is on the rise (in April 2024, 57% of the UPC cases in German local divisions were issued in English).

The importance given to the language of the prior art may be one fact that favours the rise of English as a language for UPC proceedings. With over 90% of indexed scientific articles in the natural sciences and over 52% of PCT applications since 1978 published in English[1], it is statistically more likely that any cited prior art in a UPC action will have been originally written in English.

Additionally, conducting UPC cases in English opens up a larger pool of judges – potentially reducing the risk of delays to the proceedings, with the consequent reduced likelihood that a change of language to English would be held to have a significant adverse effect on the course of proceedings.  This was a point emphasised by Dutch UPC Judge Edgar Brinkman at the Fordham conference earlier this month.

One countervailing consideration is that defendants located only in a single country of the EU may be less likely to operate in English. In their judgment, the Court of Appeal drew attention to the wording of Article 49(5) stating that the position of the defendant in particular should be taken into account – in circumstances where the outcome of the balancing of interests is equal, then the position of the defendant is the deciding factor. For smaller defendants located in UPC territories which can demonstrate that an additional burden would be imposed by having proceedings in English, it still seems likely that that they will be able to have the proceedings conducted in another of the UPC languages.

[1] By way of comparison, Chinese was the second most common language for PCT publications in 2022, with 23.4%. German, the second most-common EU language, was behind both Japanese and Korean with 5.3% of publications.


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  1. amazing, so much time and effort into the language matter, just choose the one all parties are most comfortable with and go on to the substance, sorry for venting but all these people are paid by the community and they just play games most of the time

  2. That in the case at stake, in which both companies are from the US, a change of language to that in which the patent was granted, i.e English, appears reasonable. The UPC local section of Düsseldorf might have had its reasons not to admit the change of language to English. It probably prefers to deal with the case in German.

    Without the participation of the UK in the UPC and due to the fact that the referendum on accession to the UPC has been postponed indefinitely, there is no local section in which English is mastered as mother tongue. Neither are there judges with English as mother tongue.

    To go one step further and consider English as becoming the lingua franca at the UPC is a step which goes somehow too far. It is clear that a majority of European patents granted in English (60%), but they can also be granted in German (30%) or in French (10%).

    That native English speaking representatives acting before the UPC would like English to become standard at the UPC is understandable from their point of view, but does not apply to all representatives acting before the UPC.

    That in the scientific world English is practiced by lots of people is also a fact, but most of those people do not have English as their mother tongue.

    It is not for nothing that the EPC has decided that any official language of the EPO can be used in procedures before the EPO especially in opposition and appeal on opposition. When a party timely requests it, the EPO provides, free of charge, a simultaneous interpretation in the other two official languages of the EPO.

    The situation is fundamentally different at the UPC.

    Even if the language of the proceedings before the EPO is adopted, the question of simultaneous interpretation during the hearing=OP remains.

    According to R 14 UPC, even if the parties themselves have chosen to use an additional language of the EPO as the language of proceedings, the judge-rapporteur may order in the interest of the panel to provide that judges may use in the oral hearings the official national language(s) of the country where it is situated. In case the official language is used over the chosen language, each order and decision shall be accompanied with a certified translation for enforcement.

    Simultaneous interpretation can be requested and the judge-rapporteur will decide on the request or even order simultaneous interpretation for the oral hearing, see R 109 UPC.

    Costs for simultaneous interpretation are costs of the proceedings, and hence the losing party will have to bear these costs, up to the ceilings in place, cf. R 155-157 UPC. Only costs for simultaneous interpretation for the benefit of the panel will be borne by the UPC.

    Furthermore, should English become lingua franca at the UPC, all parties not having English as their mother tongue will be heavily disfavoured. Have you ever thought of it?

    It is thus very nice that the CoA of the UPC has decided on the possibility of changing the language of proceedings, but that this can induce a large amount of costs for the losing party has never been made clear when the UPCA was ratified. The rules of procedure were not even known.

    By the way, there is another problem with the present decision of the CoA. According to Art 9(1) UPCA, any panel of the CoA shall sit in a multinational composition of five judges 3 LM and 2 TM. The present decision has only be taken by a panel of the legally qualified members. The fact that a panel of the CoA sits with only 3 LM has been criticised in an other blog. The question was even raised whether such a composition the CoA abides by the requirement of Art 6(1) ECHR.

    1. Sorry Mr Thomas, but I don’t understand your point.

      A lingua franca by at least one definition is “a language systematically used to make communication possible between groups of people who do not share a native language or dialect, particularly when it is a third language that is distinct from both of the speakers’ native languages” (see Wikipedia). Thus the fact that no countries with English as a native language (or at least none besides Malta) are members of the UPC, does not disqualify the observations made in the article above. English is clearly on its way to being the preponderant language even if it will never be the sole language, purely because it is the most common second language among all participating litigants and their representatives as well as judges. It is also a first language of a large number of litigants, as well as their representatives given that most British and Irish attorneys have rights of representation even if neither country is itself a member (yet).

      You may not like that state of affairs. But it is nevertheless how things are.

      By the way, I believe that there is at least one TQJ who has dual British and Finnish nationality and hence your assertion that there are no native English speakers among the judges is technically incorrect also.

      1. @ FRANDalorian

        I am fully aware of the meaning of the term lingua franca and that it can be a useful tool fostering communication between people having originally different languages, So to say, it is a kind of common denominator and there is nothing against this.

        I have nothing against English being a common language between different people. I said it before in another blog that my kids have the dual nationality British/French and I have relatives living in England. Most of my teaching presentations are in English to non-native speakers nad I am happy in doing so, although English is not my mother tongue. I can also accept that native speakers qury some of my formulations in English.

        Contrary to what you seem to think, I am not at all bothered by the present state of affairs. I can certainly not be accused, as was done in the past, to despise English and anything English. For me English can weli be as lingua franca, but not in a legal framework.

        When it comes to legal matters we are in a quite different situation than in every day communication.

        Litigants and their representatives having as mother tongue English will inevitably have a competitive edge or be advantaged over litigants and representatives not having the same capability. In spite of their knowledge in English, they will never have the same feeling for a language as native speakers.

        This was the meaning of my comment. By forcing English as lingua franca at the UPC, an imbalance will thus be created. That imbalance can be reduced by using simultaneous interpretation during hearings, but this has a cost for the losing party. At least at the EPO all parties are on a par as cost for simultaneous interpretation in the three official languages are borne by the EPO. This is a fundamental difference speaking against English as lingua franca at the UPC.

        One TQJ with a dual passport is by no means representative and cannot be used as an example allowing the generalisation you are claiming. In French we say” one swallow doesn’t make a spring”.

  3. “For smaller defendants located in UPC territories which can demonstrate that an additional burden would be imposed by having proceedings in English”

    That was in FFII’s EPLA 2007 analysis:


    “3. Other legal problems, such as:
    c. languages: it is not given that citizens will be able to use their language to defend themselves.”

    Defendants should not “demonstrate” anything, and should have the choice of the language.

    The UPC is the graveyard of the defendant.

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