5.4 Priority claim and priority right in the proceedings before the EPO as designated/elected Office

An international application may claim the priority of an earlier application that was filed in any state party to the Paris Convention for the Protection of Industrial Property or for any member of the World Trade Organization. Any claim to priority made for an international application thus relates to the date, or dates, claimed under the PCT (A‑III, 6.7). In the proceedings before the EPO as designated/elected Office, the priority application is (also) referred to as the "previous application" in line with the terminology used in the EPC.

The applicant in the proceedings before the EPO as designated/elected Office must (also) be the same as the applicant of the priority application or their successor in title. Any transfer of the priority right is distinct from a possible transfer of the priority application and must be assessed under the EPC, regardless of any national laws. The EPC does not set out any formal requirements for a transfer of the priority right (G 1/22 and G 2/22) (A‑III, 6.1, and F‑VI). Furthermore, where the subsequent Euro-PCT application is filed by joint applicants, it is sufficient that one of them is the previous application's applicant or their successor in title. Especially where an international application is filed by joint applicants, including the priority applicant, but without naming the priority applicant as applicant for the European designation, the mere fact of the joint filing implies an agreement between the applicants allowing all of them to rely on the priority right unless substantial facts indicate otherwise (G 1/22 and G 2/22). Further information is provided in A‑III, 6.1 and F‑VI. A translation of a priority claim only needs to be filed with the EPO in certain cases described in A‑XIII, 11.2.1.

On entry into the European phase, the applicant may need to file the results of any search carried out by or on behalf of the office of first filing for each application whose priority is claimed (A‑XIII, 11.7; A‑III, 6.12).

If the international application was filed outside the priority period, a request for restoration of the right of priority may have to be (re)filed with the EPO as designated/elected Office in accordance with Rule 49ter.2 PCT (A‑XV, 5).

The file number of the priority application, if known at the time of filing the international application, is to be provided in Box VI of the PCT request. The applicant is required to provide the file number and to submit a certified copy of the priority application to the receiving Office or the IB during the international phase, i.e. within 16 months of the (earliest) priority date, so that both will be available to the EPO on entry into the European phase. The requirement is also met if the applicant requests the receiving Office to issue and furnish to the IB the priority document under Rule 17.1(b) PCT or requests the IB to retrieve it under Rule 17.1(b-bis) PCT.

In accordance with Rule 17.2 PCT, the EPO will ask the IB for a copy of the priority document. The IB will provide the EPO with this copy promptly, but not earlier than international publication, or, where the applicant has requested early processing, not earlier than the date of the request (A‑XII, 7.1). In most cases, the IB provides the EPO with a copy of the previous application, i.e. the priority document, prior to expiry of the 31-month period. The IB will also upload the priority document to its PATENTSCOPE database, where it can be accessed by the EPO as soon as the international application is published. If the EPO receives the priority document from the IB or has access to it via PATENTSCOPE, the applicant does not need to furnish it to the EPO again.

The procedure under Rule 163(2) is to follow if a certified copy of the priority document or the file number of the priority application is not on file within the 31-month period is set out in A‑XIII, 11.2.