The questions referred to the Enlarged Board of Appeal were discussed in detail in our previous article, “G 1/22 & G 2/22: referral to Enlarged Board of Appeal on entitlement to claim priority” (see related articles). In brief, the first question related to whether the European Patent Convention (EPC) confers competence upon the EPO to assess a party’s entitlement to claim priority.

The second question related to the situation where a US patent application is filed in the name of the inventors, which is then used as the basis of a priority claim for a later Patent Cooperation Treaty (PCT) application, naming the inventors as applicants for the US only. In such cases, it had been called into question whether a co-applicant of a PCT application, who is different from the inventors named in the US priority application, can rely on the priority right in the European phase.

The Enlarged Board of Appeal has now answered in the affirmative to both questions. Most strikingly, the Enlarged Board of Appeal has held that there is a rebuttable presumption of an applicant’s entitlement to priority if the formal requirements for claiming priority are fulfilled. This applies in any case where the applicant of the priority application differs from the applicant of the later application, including the situation of the second question discussed above, and regardless of whether the later application is a PCT application.

Prior to this decision, if formal entitlement to priority was called into question, the burden of proof for a valid transfer of the priority right would have been borne by the successor in title.

Regarding the second question, the Enlarged Board of Appeal affirmed the “PCT joint applicants approach”. The Enlarged Board of Appeal considered that the joint filing of a PCT application was sufficient proof of an implied agreement on the joint use of the priority right, absent any substantial indications to the contrary.

Our initial impression is that this decision will significantly reduce the number of formal attacks on entitlement to priority during EPO opposition proceedings. A more detailed analysis of the decision and its implications will follow.

Useful links

• G 1/22 & G 2/22: referral to Enlarged Board of Appeal on entitlement to claim priority: dycip.com/g1-22-g2-22-eba-referral
• Press Communiqué concerning decision G 1/22 and G 2/22 of the Enlarged Board of Appeal, European Patent Office, 10 October 2023: dycip.com/epo-communique-10-10-2023