The applicant claiming the priority of an earlier application must be the applicant of the latter or the successor in title. The question of whether the applicant is actually entitled to claim the priority of an earlier application is not examined during the international phase. Proof of entitlement on the international filing date must be submitted in the proceedings before the EPO (only) if the validity of the priority right claimed becomes relevant. However, for a successor in title to enjoy a priority right in proceedings before the EPO, the earlier application or the priority right must have been transferred before the filing date of the international application (Box No. VIII (iii) PCT request form) and the transfer must be valid under the applicable national provisions. Any deficiencies cannot be remedied after that, and in particular not in the European phase.
Art. 4A(1) Paris Convention
PCT AG National Phase – National Chapter – EP.29
Applicants claiming the priority of an earlier application and planning to enter the European phase are therefore strongly advised to ensure that, as at the international filing date, all applicants who filed the earlier application are either mentioned as applicants in the international application or have validly transferred their rights to the applicant, or one of the applicants, in the international application. For example:
Where joint applicants file an international application and claim the priority of an earlier application, it is sufficient that one of them is the applicant who filed the earlier application or that applicant's successor in title. Since the international application has been filed jointly – which shows that the applicant who filed the earlier application consents – there is no need for a special transfer of priority right to the other (additional) applicant(s). For example:
If the earlier application was filed by several applicants, all of them must be applicants in the international application or have transferred their rights to the applicant, or one of the applicants, of the international application. It is not sufficient if only one of several applicants filing the earlier application is named as applicant in the international application. For example: