The boards consider it highly undesirable for summoned parties to announce too late, unclearly or not at all that they will not be attending. Such conduct is inconsistent both with the responsible exercise of rights and with the basic rules of courtesy (see for example T 434/95, T 65/05).

There is an equitable obligation on every party summoned to oral proceedings to inform the EPO as soon as he knows that he will not be attending as summoned (T 212/07), regardless of whether he himself or another party requested the oral proceedings and of whether or not a communication accompanied the summons to oral proceedings. If a party who has been summoned to oral proceedings fails to attend as summoned without notifying the EPO in advance, an apportionment of costs in favour of another party, who has attended as summoned, may be justified for reasons of equity in accordance with Art. 104(1) EPC 1973 (established case law, see for example T 930/92, OJ 1996, 191; T 123/05, T 972/13). As one party's non-attendance does not automatically put the other party at a disadvantage (T 273/07, T 544/94 and T 507/89), one essential question here is whether the appellant's failure to attend rendered the oral proceedings unnecessary (T 10/82, OJ 1983, 407; T 275/89, OJ 1992, 126).