Intellectual property information

Introducing the revised European Patent Office Examination Standards (2024)


We would like to introduce the revision regarding the transfer of priority rights in European patent applications, which has been a problem until now.


Clarification of practice regarding priority transfer

How should we handle cases where some of the inventors in the basic application are not listed as applicants in the PCT application?

In particular, priority rights have sometimes been denied, such as when the inventor is listed as the applicant in the basic application and the applicant in the PCT application is a company. Additionally, there was a question as to whether the EPO should determine the validity of priority transfer in the first place or whether it should be left to the domestic law of the applicant country.

With this revision, an interpretation favorable to applicants has been adopted following the decision of the Enlarged Board of Appeal. It has also been clarified that the EPO has jurisdiction to determine whether a person has the right to claim priority.


Revision details: Revised in response to Enlarged Board of Appeal decisions G 1/22 and G 2/22 (A-III-6.1)

The transfer of an application containing a priority right (or of the priority right itself) must be effected in the light of the relevant national law before the subsequent application.

The inference applies that an applicant who claims priority according to Article 88(1), Rule 52 EPC has the right to claim priority (however, this can be rebutted if there is substantive evidence).

  • With regard to the right to claim priority, the EPO considers the so-calledWe use the All Applicants approach, and if the first country application is a joint application by multiple applicants, subsequent applications must also be filed by all joint applicants., if some of the applicants in the first country application are not listed as applicants in the later application, the right to claim priority must have been transferred before the later application.
  • For example, if the national application is a joint application by A and B, and only A is listed as the applicant in the later PCT application, under the old system, in the opposition, A would have been notified by B before the filing of the PCT application. In some cases, the priority right of a PCT application was not recognized unless a document proving that the priority right had been assigned could not be presented. With this revision, if the application after transition to EP complies with the provisions of Article 88(1) EPC, Rule 52, it will be presumed that A has validly received priority assignment from B.
  • Under the old system, applicants had to prove by submitting evidence that they had the right to claim priority for the application in question.With this revision, the burden of proof has been shifted to the Examining Division, the opponent, and third parties to provide evidence that the applicant does not have the right to claim priority.