2.3.3 Rejection of opposition as inadmissible

In T 222/85 (OJ 1988, 128) the board stated that a communication under R. 57(1) EPC 1973 (R. 79(1) EPC) indicating the admissibility of an opposition was not a decision of the opposition division, and the sending of such a communication did not prevent the subsequent rejection of the notice of opposition as inadmissible under R. 56(1) EPC 1973 (R. 77(1) EPC), for example if the admissibility was challenged by the patent proprietor (see also T 621/91).

As soon as an opposition had been rejected as inadmissible, the opposition procedure was regarded as legally terminated and substantive examination could no longer be initiated. The inadmissibility of an opposition, when finally decided, or an appeal, had the effect of transferring the European patent to the national jurisdiction of the designated states, which then assumed sole responsibility for assessing the patent's validity with reference to their own legislation. The board therefore came to the conclusion that it was inconsistent with the procedural principle referred to above for the decision rejecting the opposition as inadmissible to consider that opposition's merits. Remarks on substantive matters in a decision rejecting the opposition as inadmissible had no legal effect. Such remarks should, in principle, be avoided, as a procedural deficiency of this kind could result in legal uncertainty during the national phase and could disadvantage either the proprietor or the opponent (T 925/91, OJ 1995, 469; see also T 328/87, OJ 1992, 701).