a) Decision announced in oral proceedings 

The written reasons for a decision delivered during oral proceedings can only be signed by members of the deciding body who took part in the oral proceedings. The same principle applies if between the orally delivered decision and the written decision proceedings in accordance with R. 58(4) EPC 1973 (R. 82(1) EPC) have taken place (T 390/86, OJ 1989, 30). In T 390/86 the board also stated that in a case where a final substantive decision has been given orally by an opposition division during oral proceedings, if the subsequent written decision giving the reasons for such oral substantive decision is signed by persons who did not constitute the opposition division during the oral proceedings, the decision is invalid.

In T 243/87 the board declared a decision to be null and void where one of the three signatures was provided by a member who had not attended the oral proceedings.

In T 3085/19 the board found that the missing signature of the legally qualified member on page 2 of EPO Form 2009.2 and on EPO Form 2906 gave the impression that the decision had not been consented to by all the members responsible for the decision. Therefore, it could not be concluded that all members who had participated in the oral proceedings had authorised the decision. This was qualified by the board as a substantial procedural violation.

Similarly, in T 289/23 the board considered the requirement pursuant to R. 113(1) EPC not complied with since the decision had not been signed by the legally qualified member. Moreover, there was no indication that this member had been for some reason unable to act at the time the written decision had had to be issued, and in any event none of the other members had signed or authenticated the decision on their behalf. This was considered a substantial procedural violation.

In T 572/19 the board found that the missing signature could not be remedied under R. 140 EPC, with the Chair belatedly signing the EPO Form 2339 on behalf of the legally qualified member, since the mistake was not an obvious one within the meaning of R. 140 EPC. The board considered the missing signature a substantial procedural violation, and the appealed decision invalid.