Skip to main content

United States Applicants, What Are Your Priorities?  EPO Enlarged Board of Appeal Reviews Joint-Applicants Approach To Priority Claims in G1/22 & G2/22

Feb 14, 2022

Table of contents
    Michael Nielsen

    I work as a European & UK patent attorney at Berggren, helping clients to secure and protect the rights for their inventions across Europe. I enjoy taking the complicated field of European patent law and turning it into concrete, relevant advice for our clients and their businesses.

    A new referral to the European Patent Office’s Enlarged Board of Appeal has the potential to affect the validity of priority claims made in huge numbers of Euro-PCT applications filed by US-based corporate or institutional applicants before the America Invents Act came into effect.

    Formal Priority

    Article 87 EPC sets out the rules by which a subsequent application can validly claim priority to a first application for the same invention. Some of these rules are formal, such as requirements on the identity of the applicants for the first and subsequent applications, and some are substantive, such as the requirement that the first and subsequent applications relate to the same invention.

    The issue of formal priority entitlement often comes up in European Patent Office opposition proceedings and in the appeal proceedings that often follow. Many words have been spoken and written about the seemingly simple requirement that the applicant for the subsequent application be the same as the applicant for the first application or their successor in title. Historically, the EPO and the boards of appeal have taken a strict line on formal priority, requiring that the applicants for both applications are identical or that transfers of priority rights were executed before the subsequent application was filed, for example. See, for example, the well-known EPO Board of Appeal decision in T 844/18 in connection with an EP application related to CRISPR biotechnology.

    The Joint-Applicants Approach

    Take the common example of a first application filed in the USA and a subsequent PCT application, which claims priority to US application. First applications filed in the USA often list the inventors as the applicant and, indeed, before the America Invents Act came into force, patents in the United States could only be applied for by the inventors.

    For PCT applications pre-AIA it was universal practice to list the inventors as applicants for the United States and the “real” applicant, typically a corporate or institutional body such as the inventors’ employer, as the applicant for all other states. In the European regional phase of such a PCT application, where the inventors are applicants for the first application and the inventors’ employer is applicant for the subsequent in Europe, is the inventors’ employer legally entitled to claim priority from the US application?

    The opposition divisions of the European Patent Office have faced this question many times and, in response, came up with the so-called “joint-applicants approach” to resolve the (perhaps overly harsh) approach to formal priority in these common cases. Under the joint-applicants approach, as long as all of the applicants of the first application – e.g. the US application – are listed as applicants on the subsequent application – e.g. the PCT application – then the applicants for the subsequent application are considered to be legally entitled to claim priority to the first application, even if the applicants for the subsequent application include other entities. In the situation described above, it’s enough that the inventors were listed on the PCT application as applicants only for the USA.

    New Referral

    The joint-applicants approach has now come under scrutiny by the boards of appeal of the EPO in consolidated appeal cases T 1513/17 and T 2719/19, where the board considers the validity of the joint-applicants approach to be decisive for the decision. Moreover, the board considers that the issue concerns point of law of fundamental importance that is relevant to many pending cases before opposition divisions and boards of appeal. As a result, the board has asked the Enlarged Board of Appeal to consider the legitimacy of the joint-applicants approach.

    Specifically, the following questions have been referred to the Enlarged Board:

    Ι. Does the EPC confer jurisdiction on the EPO to determine whether a party validly claims to be a successor in title as referred to in Article 87(1)(b) EPC?

    ΙΙ. If question I is answered in the affirmative:

    Can a party B validly rely on the priority right claimed in a PCT-application for the purpose of claiming priority rights under Article 87(1) EPC in the case where:

    1. a PCT-application designates party A as applicant for the US only and party B as applicant for other designated States, including regional European patent protection and

    2. the PCT-application claims priority from an earlier patent application that designates party A as the applicant and

    3. the priority claimed in the PCT-application is in compliance with Article 4 of the Paris Convention?

    The first question asks whether the EPO should even be trying to assess whether a party is the legitimate successor in title of the applicant for the first application. The second question explicitly asks whether the joint-applicants approach is valid.


    The Enlarged Board’s decision in this case has the potential to affect essentially every PCT application filed by a US-based corporate or university applicant before the America Invents Act came into effect.

    Even though that was now a decade ago, the last PCT applications filed under the old regime are only halfway through their 20-year term. That puts many of those applications in the crosshairs of the European Patent Office’s opposition divisions and board of appeal, which will be bound by a decision of the Enlarged Board on this issue. Furthermore, while national courts are not bound by decisions of the Enlarged Board, the Enlarged Board’s decisions are nevertheless very persuasive. Should the Enlarged Board decide that the joint-applicants approach is not valid, many granted patents could therefore be exposed to new attacks both in EPO opposition and appeal proceedings and before national courts and in the upcoming Unified Patent Court. US-based applicants and patentees will want to pay close attention to the Enlarged Board’s decision.

    The case also highlights the importance of having all your priority ducks are in a row before filing a PCT application in the name of a different applicant to the priority application. This is still common where the priority application is a US provisional application. In practice, this means having transfer of at least the priority right, if not all rights in the invention, from the inventors to the PCT applicant executed before the PCT application is filed, i.e. within the priority year. Regardless of the Enlarged Board’s decision in this case, if the transfers have been properly and timely executed, the formal requirements for priority should stand scrutiny.

    Stay up to date with IP news

    Subscribe to our newsletter to get latest articles.