Published October 17, 2023

The Enlarged Board has issued its decision in consolidated cases G 1/22 and G 2/22. It concluded that the EPO is competent to assess priority entitlement and that there is a rebuttable presumption that an applicant claiming priority in accordance with the formal requirements under the EPC is entitled to do so.


The referral by Technical Board of Appeal 3.3.04 in consolidated cases T 1513/17 and T 2719/19 (OJ EPO 2022, A92) concerned, firstly, the question of whether the EPO is competent to assess a party’s entitlement to claim priority. Secondly, the referral addressed a situation where inventors file a US patent application which is then used as a priority application for a later PCT application in which the inventors are named as applicants for the US only, whereas for European patent protection (legal) persons other than the inventors are named. In such a situation, the question arises whether the co-applicant of a PCT application who is different from the inventors named in the US priority application can in the European phase validly rely on the priority right under Article 87(1) EPC.

In the two cases underlying the referral, the Opposition Division and the Examining Division respectively found the priority claim to be invalid because not all inventors who were named as applicants in the US patent application had assigned the priority right to the applicants of the respective European patent applications before the filing of the PCT application.

Under Article 87(1) EPC “[a]ny person who has duly filed […] an application for a patent […] or their successor in title, shall enjoy, for the purpose of filing a European patent application in respect of the same invention, a right of priority during a period of 12 months from the date of filing of the first application”.

Key considerations

The Enlarged Board distinguished between the right to file a European patent application (i.e., the lawful title to the application and to the ensuing patent) and the right to claim the priority date for that application (i.e., the “right of priority” referred to in Article 87(1) EPC). Under Article 60(3) EPC the EPO was not competent to assess the applicant’s entitlement to the patent application. This provision, however, did not apply to the right of priority referred to in Article 87(1) EPC, neither directly nor by analogy. Thus, the EPO was competent to assess an applicant’s entitlement to priority.

According to the Enlarged Board, the priority right and its transfer is a matter governed by the autonomous law of the EPC. The applicant’s entitlement to priority is presumed to exist if the formal requirements for claiming priority are fulfilled. This presumption is justified because (i) all parties involved normally have an interest that an application may benefit from a priority right, (ii) there are no formal requirements for the transfer of priority rights, and (iii) the applicant of the priority application has to provide support to the applicant claiming priority (e.g., by providing unpublished documents). The presumption is rebuttable and applies in any case where the priority applicant is not identical to the subsequent applicant, and regardless of whether the subsequent application is a PCT application.

The Enlarged Board further held that the rebuttable presumption also applied in the situation described in referred question II (OJ EPO 2022, A92). For this situation, the Enlarged Board additionally endorsed the interpretation of the joint filing of a PCT application as sufficient proof for an implied agreement on the joint use of the priority right, unless there were substantial indications to the contrary.


The order by the Enlarged Board of Appeal reads as follows:

  1. The European Patent Office is competent to assess whether a party is entitled to claim priority under Article 87(1) EPC.

There is a rebuttable presumption under the autonomous law of the EPC that the applicant claiming priority in accordance with Article 88(1) EPC and the corresponding Implementing Regulations is entitled to claim priority.

2. The rebuttable presumption also applies in situations where the European patent application derives from a PCT application and/or where the priority applicant(s) are not identical with the subsequent applicant(s).

In a situation where a PCT application is jointly filed by parties A and B, (i) designating party A for one or more designated States and party B for one or more other designated States, and (ii) claiming priority from an earlier patent application designating party A as the applicant, the joint filing implies an agreement between parties A and B allowing party B to rely on the priority, unless there are substantial factual indications to the contrary.

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