c) Prima facie relevance for assessment of patentability 

(i) Not a sufficient justification for late submission 

As observed in T 731/16 (citing CLB, 9th edn. 2019, V.A.4.13.2), it was the boards' established case law that a decisive criterion for admitting late-filed documents was their prima facie relevance. Such material needed to be prima facie highly relevant in the sense that it was highly likely to prejudice maintenance of the European patent.

In many decisions in which the revised (2020) version of Art. 13(1) RPBA is applied, boards have pointed out that besides the listed criteria further decisive criteria for admitting late-filed documents could be their prima facie relevance and whether they introduced any complex matter (see T 1213/19 date: 2022-09-23, citing T 731/16, T 2796/17 and T 310/18; for a contrary view, see T 1684/17, in which the board notes that prima facie relevance is not mentioned in Art. 13(1) RPBA). In T 361/19 the board considered that admission of a late filed, but prima facie novelty-destroying document was, in principle, covered by Art. 114 EPC and also by Art. 13(1) RPBA. In the board's view these provisions leave sufficient discretion to a board to admit such documents. However, numerous decisions illustrate that, while this aspect is considered, it does not necessarily prevail over other criteria, in particular the time of filing (see e.g. T 361/19 T 1203/16, T 1333/20).

In T 1203/16 the appellant (opponent) submitted, in reply to the preliminary opinion of the board, new lines of attack based on a document considered in opposition, and additionally, a new novelty objection based on a new document. As justification for these late amendments to its case, the appellant merely argued that the new lines of attack were relevant for assessing the patentability of the opposed patent and avoiding maintenance of a patent not fulfilling the requirements of the EPC. The board emphasised that such a justification was not sufficient. These new lines of attack could and should have been filed before. The board emphasised the leading principle of the RPBA, namely that on appeal parties' cases should be complete at a very early stage. It therefore decided in exercise of its discretion not to admit the new lines of attack and the corresponding document into the proceedings pursuant to Art. 12(4) RPBA 2007, Art. 13(1) RPBA and Art. 13(1) and (3) RPBA 2007.

(ii) Examples where prima facie relevance was considered, and the late submission taken into account 

In T 1213/19 date: 2022-09-23 the appellant (opponent) justified the late filing of D8, more than six months after the filing of the statement of grounds of appeal, by the fact that it was found by chance during a search for another patent. In the board’s view, the document could have been found earlier as it lay in the same technical field as the patent, had been published five years before the end of the opposition period and seemed to have been pivotal in the examination proceedings of a divisional application derived from the European patent application on which the patent was based. However, the board weighed these aspects against the considerations that the respondent must have been familiar with the content of this document and that, at first glance, D8 could reasonably be expected to prejudice the maintenance of the patent. In view of the above, the board exercised its discretion to admit document D8 under Art. 13(1) RPBA.

For a further case in which prima facie relevance was one criterion among others that were taken into account and the relevant submissions were admitted, see e.g. T 34/18 (prima facie relevance of evidence rebutting a public prior use, summarised above in chapter V.A.4.4.6 a) (xi)).

(iii) Example where prima facie relevance did not prevail over other criteria 

In T 1333/20 the board held that in the case in hand the alleged relevance of the new submissions (objections under Art. 123(2) EPC) did not prevail over the fact that the respondent could and should have submitted them in a substantiated manner when forming its appeal case, namely, in the case in hand, with its reply to the statement setting out the grounds of appeal (Art. 12(3) RPBA).

(iv) Examples where late submissions were rejected as inadmissible for lack of prima facie relevance 

In T 731/16 citation D12 had only been filed in response to the board's communication under Art. 15(1) RPBA 2007. In the board's view, it was out of the question that it would have been self-evident for the skilled person to combine the teaching of D4, a citation already on file, with that of newly filed D12. It therefore held that D12 was not highly relevant prior art and refused to admit it.

In T 2796/17 prima facie relevance was one of several factors the board considered in exercising its discretion (Art. 13(1) RPBA 2007, Art. 25(1) RPBA and Art. 13 RPBA 2007, Art. 25(3) RPBA). The board found that the new submission (an inventive-step objection to the subject-matter of claim 1, based on a combination of two documents filed with the notice of opposition) was not prima facie relevant, because the appellant (opponent) had not substantiated why the skilled person starting from the asserted closest prior art would have consulted the second document (without hindsight) or how that document disclosed the features added to the new main request. Not only had the appellant, without providing any justification, raised the objection for the first time at the oral proceedings, but the objection involved a complex new set of facts. The board therefore refused to admit it.

For further cases where (prima facie) relevance was considered but not acknowledged, see e.g. T 102/16 (concerning D26), T 1877/16 (concerning D20 and D21).