c) Suitable evidence of valid transfer, formal requirements 

In T 205/14 the board disagreed with the reasoning of the board in T 62/05 that the transfer had to be proven in a formal way, applying an equally high standard of proof as that required by Art. 72 EPC 1973. Art. 72 EPC 1973 set out formal requirements for a valid assignment of a European patent application and thereby limited the means of giving or obtaining evidence for determining such a transfer. No reason was apparent for applying it by analogy in the context of a transfer of the priority right preceding a subsequent filing. To do so in view of a subsequent European patent application would, in the case of a European first filing, ignore the fact that the priority right is a right independent of the right to the first application and, in the case of a non-European first filing, that Art. 72 EPC 1973 does not govern the relationship between the applicant of a European patent application and a different applicant of a distinct first application. The board came to the same conclusion as the German Federal Supreme Court in its decision of 16 April 2013 that Art. 87 EPC does not require a formal and separate assignment as provided by Art. 72 EPC. See also in this chapter II.D.2.3.

In T 493/06 it was held that the respondents had provided sufficient proof of the assignment of priority rights. In the board's view, even a copy of an assignment agreement could be sufficient provided that evidence was supplied that the content of the copy was identical to that of the original document.

According to the board in T 1103/15, if a party made statements about conclusions to be drawn on the basis of the applicable national law, it had to file suitable evidence, for example by filing as documents adequate copies of such laws and/or as appropriate by filing as expert evidence the opinions of a suitably qualified lawyer in the relevant jurisdiction (T 74/00).