EPO express

Who is entiteled to the right of priority ?

This provision was implemented in Article 87(1) EPC

From the wording of the Paris Convention and Art. 87 EPC it is clear that the right to claim priority belongs to the applicant or his successor in title. As long as at least one applicant of the priority application and one applicant of the later European Patent application that claims the priority to the priority applications are identical no further prove is required. Issues arise only where the applicant of the priority application and the applicant of the later European patent application that claims the priority to the priority application differ. Then, if the priority right is challenged, the applicant of the later European patent application, who claims to have the right to the priority, has to prove that he is entiteled to the prirority right, for example as a successor in title. Such challenges arise for example in an opposition proceeding, where a third party presents novelty or inventive step destroying prior art, that falls in-between the priority date and the application date of the later application.

The Board of Appeal of the European Patent Office rendered in T 1008/96 a decision that the validity of a priority claim has to be satisfactory proven to the EPO by the party who claims the right to the priority of an earlier application. In this case applicant BD filed in Italy in January 1987 and June 1987 two utility model applications for a gasket of elastomer material. Company G, filed a European patent application in January 2018, just a day before the end of the priority year. As could be seen form the documents, the applicant of the priority application and the applicant of the later European patent application were not identical.

An opponent provided drawings and invoices that proved to the Board of Appeals satisfaction that the invention as claimed in the priority application was used in public before the later European patent application, but after the priority application date. Therefore, the validity of the right to the priority was crucial whether this prior use was novelty destroying or not. The applicant of the later European Patent application presented a declaration of BD, in which she had sworn before a public notary in April 1988 that she had assigned to the utility model applications to G. It seems that according to Italian law a formal assignment of the priority right is not compulsory and an oral agreement would be equally valid. As the transfer of a priority right in Italy is not subject to any formal requirements, the declaration of the applicant of the priority application may have been a sufficient prove, that the priority right was transferred before the application date of the later European patent application.

The opponent however, provided a decision of the court of Monza, according to which BD is the owner of an Italian patent, which is based on the first priority application. So, the Board of Appeal was confronted with two pieces of evidence which would appear mutually exclusive. As the court of Monza pointed to the fact that there was not any evidence of the relationship which would link BD to the different owner G of the European patent, the Board of appeal came to the conclusion that the owner of the European patent had failed to prove that he is the successor in title of the two Italian utility model applications from which he claims priority and which were filed by BD.

The Board also concluded that the documents offered to prove prior use were sufficient. In summary the Board of Appeal considered the prior use as novelty destroying because the claimed priorities were invalid and consequently revoked the European patent.

Some decisions of the board of appeal imposed harsh conditions on the applicant he had to meet when transferring the right of priority to him. Finally, decission T 0205/14 introduced less formal conditions to be met. If a transfer of the right of priority in the country where the priority applications were filed or the country of the applicant do not impose special reqeuirements, such as a contract signed in the presence of a public notary, the EPO will accept these conditions, if they have been proven to the EPO's satisfaction.

However, the board of appeal made it clear that a priority right cannot be transferred retroactivly under the provisions of the EPC. It seems to be obvious that the public has to be protected from unrelated patent applicants trading priority rights to gain a legal position they never had intended in the first place.