According to an approach frequently adopted by the boards a request after arrangement of the oral proceedings may be admitted and considered at the board's discretion (i) if sound reasons exist for filing this request so far into the proceedings (this may be the case when amendments are occasioned by developments during the proceedings), (ii) if the auxiliary request does not extend the scope of discussion as determined by the grounds of appeal and the respondent's reply (iii) if the auxiliary request is clearly or obviously allowable (this means that it must be immediately apparent to the board, with little investigative effort on its part, that the amendments made successfully address the issue raised without giving rise to new ones) (see in particular T 1634/09, T 484/07, T 447/09, T 2344/09, T 1925/10, T 416/12, T 1605/14 and T 385/15). Such amendments should in principle allow the granting of a patent based thereon (T 1748/08, T 2250/08).

In T 81/03, the board found that requests filed shortly before the minimum deadline set by it in the summons to the oral proceedings had to be regarded as belated where they contained points which could only be dealt with properly in an additional written phase (T 518/08).

In T 253/06, the board held that it was permissible under Art. 13(3) RPBA 2007 to regard as belated auxiliary requests filed after oral proceedings had been arranged but within the prescribed period, if those requests were not substantiated, i.e. not accompanied by reasons explaining why the amendments had been made and how they were intended to overcome the objections raised in the course of the proceedings (T 2422/09, T 351/10, T 2497/10). This conclusion holds all the more true, if such an unsubstantiated request is filed only shortly before the oral proceedings. In this respect an ex-parte is not different from an inter-partes case (T 1278/10).

Amended claims filed at such a late stage should be clearly allowable in the sense that it can be quickly ascertained that they overcome all outstanding issues without raising new ones (T 1126/97,T 1993/07, T 183/09).

Similarly, in T 1443/05, the board refused to admit the auxiliary request under Art. 13(3) RPBA 2007 because, as a result of its late filing, the question whether it met the requirements of Art. 123(3) EPC 1973 could not be answered without adjourning the oral proceedings (see also T 1026/03, T 1305/05, T 455/06).