e) Complexity of the amendment 

As pointed out in T 1213/19 date: 2022-09-23, besides the criteria listed in Art. 13(1) RPBA, according to established case law, further decisive criteria for admitting late-filed documents under Art. 13(1) RPBA can be their prima facie relevance and whether they introduce any complex matter (T 731/16, T 2796/17 and T 310/18).

(i) New objection relying on previously discussed documents 

In T 310/18 the appellant (opponent) raised an objection regarding lack of inventive step starting from D2 in view of D15 for the first time about a month before the oral proceedings. However, since an attack starting from D15 in view of D2 had already been dealt with in the decision under appeal, the relevant technical content of these documents had been discussed extensively during the earlier stages of the appeal proceedings. The board considered that starting from D2 instead of D15 did not introduce any complex matters but merely relied on a combination of the previously discussed features. Under these circumstances the board decided to admit the objection into the proceedings (Art. 13 RPBA 2007, Art. 13(1) and (3) RPBA, the 2020 version of Art. 13(2) RPBA not yet being applicable).

However, in T 140/15 a late-filed new objection based on a known combination of documents was not admitted. The board held that it made no difference that an objection based on the same documents but in reverse order had been raised earlier in the proceedings; this was still a new objection and its discussion would not necessarily take a similar course to that of the earlier one.

(ii) Mere development of previous submissions 

In T 3212/19 the submission of documents which had already been submitted with the grounds for opposition but not yet in the appeal proceedings, was considered in the case at hand to be just a development in the appellant's appeal case. The board considered that these documents simply served to help explain the operating modes of the devices described in documents already forming part of the proceedings. The board therefore saw no reason not to admit them into the appeal proceedings. See similarly, T 2271/17 (new facts presented in terms of references to specific documents, mere development of objections outlined previously, adequate time for respondent to react thereto).

(iii) Examples where submissions introduced new complexity and were not admitted 

In T 2227/15, applying Art. 13(1) RPBA as well as Art. 13(1) and (3) RPBA 2007 and considering all the circumstances of the case, the board concluded that admitting the new inventive-step attack into the proceedings would not only substantially add to and considerably change the complexity of the matter to be discussed, but would also be contrary to the need for procedural economy and would take the respondent by surprise.

In T 1303/18 the board did not admit the appellant’s (proprietor’s) defence (raised for the first time after the filing of the grounds of appeal and the replies) relying on entitlement to partial priority into the proceedings. The required new factual assessment would have been complex and the appellant had provided no justification for this late amendment.

See also e.g. T 2796/17 (summarised in chapter V.A.4.4.6c) (iv)) and T 1217/17.