In its decision on the merged proceedings G 1/22 and G 2/22, the Enlarged Board of Appeal recently confirmed that the EPO has competence to assess whether a party has a priority claim based on the EPC.  This also applies if the priority right has been assigned to a legal successor. The formal requirements for such an assignment are set very low by the Enlarged Board of Appeal, which confirms the possibility of an implicit assignment.

The legal succession of priority rights, in particular the validity of assignments of priority rights, frequently raises questions in practice due to their international character. This is because transfers of private rights – such as priority rights – and underlying agreements are generally subject to national civil law. Since the origin, existence and effects of priority rights are governed only by the EPC (and by the Paris Convention in its relationship to the EPC), the Enlarged Board of Appeal is of the opinion that priority rights according to Article 87(1) EPC are autonomous rights under the EPC and should also be judged only in the context of the EPC, i.e. independently of national laws. In this context, according to the Enlarged Board of Appeal, it is justified to consider an agreement implied by the joint filing of a subsequent application as an agreement subject only to the autonomous law of the EPC. In this respect, the EPO is competent to assess whether a party is entitled to priority according to Article 87(1) EPC.

In principle, according to the autonomous law of the EPC, there is a rebuttable presumption that the applicant claiming priority is entitled to claim priority. Nothing else applies in the case where the priority right has been assigned to a legal successor. It was questionable to what extent a joint filing of a subsequent application constitutes an informal or silent (implicit) and effective agreement between two parties, if only one of the parties was an applicant of the earlier priority application. In this respect, the Enlarged Board of Appeal is of the opinion that if national laws already do not provide for any or only minor formal requirements for the assignment of priority rights, the autonomous law of the EPC should also not provide for any formal requirements higher than the national laws which may be relevant in connection with a European application. Rather, the EPO should be guided by the lowest standards of national law and accept implied assignments of priority rights in almost all circumstances. For example, the autonomous law of the EPC should not require that the assignment of priority rights be in writing or signed by the parties, as this would be a high threshold in view of national law. The Enlarged Board of Appeal concludes, based on the low formal requirements, that in the absence of unambiguous indications to the contrary, a joint subsequent application is sufficient evidence that the parties have entered into an implied agreement allowing one party to rely on the priority right established by the filing of another party’s priority application.

Almost incidentally, the Enlarged Board of Appeal also commented on the requirement that the assignment of the priority right must be completed prior to the filing of a subsequent European patent application. Even this requirement was questionable. If there are national legal systems that allow a subsequent (“nunc pro tunc”) assignment of priority rights, the EPO should not apply higher standards here either.

In summary, the assessment of whether a party is entitled to priority according to Article 87(1) EPC is, in the view of the Enlarged Board of Appeal, a question of autonomous law of the EPC, i.e. independent of national laws, and the EPO is competent in this respect. The formal requirements for the assignment of priority rights are set very low by the Enlarged Board of Appeal, which should be a great convenience for patent applicants in practice. Thus, in the future, it should generally be presumed that a priority claim exists in favor of the later applicant of a European patent application, even if the latter is not identical with the applicant of the earlier priority application.