a) Determination of the applicable national law 

With regard to the formal requirements for the transfer of the right of priority, the board in T 1201/14 observed that, as the EPC contained neither guidance nor conflict of law provisions for that purpose, national law was commonly relied upon by the departments of the EPO entrusted with the procedure. The board also acknowledged that there was no established jurisprudence of the boards as to the national law generally applicable to this question. As noted by the board in T 205/14, in some cases the determination of the applicable national law seemed to have been straightforward in view of the circumstances of the respective cases. In J 19/87 all circumstances relevant to the transfer of the right to priority (residence, place of business, state of the first filing, assignment contracts) related to UK law, and the board applied this national law to the question of entitlement to priority. Similarly, in T 1008/96 all circumstances relevant to the transfer of the right to priority were connected with Italy and thus with Italian law. See also T 493/06 and T 725/14.

In T 160/13, concerning a transfer within a corporate group, the patent in suit was filed as an international application by an affiliate with a place of business in France. It claimed the priority of a German utility model application, which had been filed by an affiliate with place of business in Germany. Here, the place of business of the transferor, the state of filing of the first application and the assignment declaration by the transferor (e-mails sent by an employee of the German affiliate) were factual elements connected to German territory. Only the place of business of the transferee tended to the application of a law other than German law. The board confirmed that the opposition division had rightly examined the transfer of the priority right on the basis of German law.

In T 205/14 the board considered both the law applicable to the legal relationship between the transferor and the transferee of the priority right and the law of the state of filing of the first application and concluded that the former – in this case the law of the state of the employment relationship between the applicants (inventors) of the US provisional applications from which priority was claimed and the patent proprietor (here the law of Israel) – determined the transfer. See also T 517/14.

In several cases the boards did not have to decide which law was applicable because succession under Art. 87(1) EPC was assessed under different national laws for the same set of facts with the same result. See e.g. T 577/11, where the board found that none of the appellant’s arguments, which were based on the applicability of Italian and Dutch law, led to a finding favourable for the applicant. See also T 1201/14.