An applicant wishing to claim priority must file a declaration of priority indicating:[Art. 88(1); Rule 52(1); Rule 41(2)(g); Art. 90(4); ]

The declaration of priority shall preferably be made on filing the European patent application (Rule 52(2)). In such a case the declaration of priority, indicating at least the date on which and the country for which the earlier application was filed, should be present in the request for grant form (Rule 41(2)(g)). However, if a priority claim is added or corrected after the request for grant form has been filed (see A‑III, 6.5.1 and A-III, 6.5.2), the applicant will not be invited by the EPO to file a corrected request for grant.

The time limit for filing the certified copy of the priority document is the same as the time limit for making the priority claim (see A‑III, 6.5.1 and A-III, 6.7). Consequently, where:

the requirements of Rule 52(1) are met.

6.5.1 Filing a new priority claim

6.5.2 Correcting an existing priority claim

6.5.3 Deficiencies in the priority claim and loss of the priority right