2.7.4 Timing of transfer

Concerning succession in title to the right of priority, according to T 1201/14, it was clear from the wording of Art. 87(1) EPC 1973 alone that this must have already taken place when the subsequent application is filed. The board in T 577/11 had already held that a succession in title that occurred after the filing date of the subsequent application was not sufficient to comply with the requirements of Art. 87(1) EPC 1973. The board in T 1201/14 took the view that, even if a retroactive transfer such as the "nunc pro tunc" assignment under US law invoked by the appellant was allowable under US law, it would not be acceptable under Art. 87(1) EPC 1973.

In T 1946/21 the board observed that the case law had not been settled on the question of whether the transfer agreement must have been concluded (T 577/11), and thus the assignment must have been effective, before the filing date of the subsequent application or whether it was sufficient for this to have been done on the same day but before the actual filing. The board was not aware of any case before the boards where this question was decisive. Therefore, any reference in the case law to "before the filing" or "before the date of filing" was irrelevant (see e.g. T 1201/14). The board concluded that it was sufficient for the applicant or patent proprietor to demonstrate that the assignment of the priority right was effective before the subsequent application was filed. The law did not set forth any other condition. In particular, the assignment need not be effective before the filing date of the subsequent application.

See, however, in this chapter II.D.2.3.