3.1.1 Basic principles

The EPO departments must ascertain the relevance of evidence submitted to them before deciding whether to admit or reject it. EPO departments do indeed have some discretion in admitting evidence offered, for example where (i) it is no longer needed because the fact at issue is not contested by the other party, (ii) where the decision will in any case go in favour of the party offering it, (iii) where it is submitted very late in the proceedings and is considered immaterial, or (iv) where for some other reason it cannot affect the outcome (e.g. evidence offered in an inadmissibly late-filed opposition) (T 142/97, OJ 2000, 358).

Decision G 2/21 (OJ 2023, A85) summarises in point 42 of the Reasons the key points in case law, i.e. that all means of giving or obtaining evidence set out in Art. 117(1) EPC are at the discretion of the deciding body and ordered only if that body deems them to be necessary (T 798/93).

In T 798/93 (OJ 1997, 363) the board observed that the only specific means requested was a sworn statement in writing but, in the absence of any legitimate doubt as to the opponent's identity, the board considered that this was neither useful nor necessary.

If the evidence offered as proof of contested facts essential to the settlement of the dispute is decisive, the body hearing the case must, as a rule, order that it be taken (T 474/04, OJ 2006, 129, about witnesses, also cited in G 2/21 point 42 of the Reasons, T 778/21 point 3.4.4 of the Reasons, T 2659/17).

All appropriate offers of evidence made by the parties should be taken up. As a rule, it cannot be considered to be in keeping with good procedural practice for an opposition division not to take up an opportunity to hear a witness or party in evidence (T 329/02; see T 860/01 on the extent of the discretionary power of the first-instance department and T 1738/21 for a summary of the applicable principles from the case law).

All the cases cited below relate first and foremost to requests to hear witnesses. The sub-headings are aimed at guiding readers to more specific aspects. Since the reasons for a decision may touch on several aspects, the abstracts may also deal with points not alluded to in the heading.