a) Discretionary decision to admit or not admit amendments – legal basis 

Unlike R. 137(3) EPC (R. 86(3) EPC 1973), R. 80 EPC (R. 57a EPC 1973) does not specify a point in time up to which the proprietor may amend the description, claims and drawings in accordance with the requirements of this provision.

According to the case law of the boards of appeal, however, the proprietor has no right to have amendments admitted at any stage of the opposition proceedings that it chooses. Proposed amendments may be disregarded in particular if submitted late in the proceedings (for early decisions setting out this principle, see e.g. T 153/85, OJ 1988, 1; T 406/86, OJ 1989, 302; T 295/87, OJ 1990, 470; T 132/92). The boards have derived this principle from different legal provisions.

Early decisions derived the discretion of the opposition division from Art. 101(2) EPC 1973 read together with R. 57(1) and 58(2) EPC 1973 (see e. g. T 406/86, OJ 1989, 302; T 132/92).

In T 382/97 the board explained that R. 57a EPC 1973 (R. 80 EPC) and R. 71a EPC 1973 (R. 116 EPC) together governed the procedural preconditions for amendments to a patent by its proprietor before the opposition division, which amendments of course had to comply with Art. 123(2) and (3) EPC 1973: R. 57a EPC 1973 (R. 80 EPC) created the legal basis for amendment, and R. 71a EPC 1973 (R. 116 EPC) governed the deadline for doing so.

Likewise in T 688/16 the board held that discretion not to admit late-filed requests was conferred by R. 116(2) EPC. That discretion was conditional on a communication stating that grounds prejudiced the maintenance of the patent. In the case at issue, however, the opposition division had not issued any such negative communication but only one stating its provisional opinion that none of the grounds for opposition prejudiced maintenance of the patent as granted (distinguished in T 966/17).

In many decisions the boards have relied on Art. 114(2) EPC (sometimes in conjunction with R. 71a EPC 1973 or R. 116 EPC as its implementing provision) as the legal basis for the opposition division's discretion to disregard late-filed requests (see in particular T 1105/98, which cited the preparatory documents to R. 71a EPC 1973, without however distinguishing between paragraphs 1 and 2 of R. 71a EPC 1973; see also e.g. T 4/98, T 171/03, T 811/08, T 1351/10, T 2069/11, T 66/12, T 1214/12, T 2385/12, T 487/13, T 108/14, T 2332/15; for recent decisions, see e.g. T 44/17, T 350/17 and T 879/18). T 1855/13 subsumed "submissions" (here the first auxiliary request) under the term "facts" in Art. 114(2) EPC. For the contrary view according to which Art. 114(2) EPC cannot serve as a basis for the opposition division's discretion to admit or refuse requests, see, however, T 755/96, T 281/99, T 688/16, T 754/16.

In T 755/96 the board held that the power of the opposition division to accept or refuse late-filed new facts or evidence was governed by Art. 114(2) EPC 1973, the discretionary power to refuse new requests for amendments by Art. 123 EPC 1973 and the corresponding implementing regulations, i.e. R. 57a EPC 1973 (R. 80 EPC) (see also T 1903/13, which cites Art. 123(1) EPC as the legal basis for the discretion of the boards in opposition appeal proceedings). Several recent decisions have likewise considered Art. 123 EPC (albeit in conjunction with R. 79(1) and 81(3) EPC) to be the legal basis for this discretion: T 966/17, R 6/19 and T 256/19 (J 14/19 stated that Art. 123(1) EPC could serve as an additional legal basis besides Art. 114(2) EPC).

In T 966/17 the board considered that the opposition division's discretion in deciding whether to admit amended claims followed in essence from Art. 123(1) EPC (first sentence) in conjunction with R. 79(1) and 81(3) EPC and stated the following reasons. Art. 123(1) EPC provided that a European patent application or a European patent could be amended in proceedings before the EPO in accordance with the Implementing Regulations. In opposition proceedings, R. 79(1) EPC allowed the patent proprietor to amend the description, claims and drawings within a period set by the opposition division. Later amendments, by contrast, were admissible only at the opposition division's discretion, as was clear from R. 81(3) EPC for instance ("shall, where necessary, be given the opportunity").

In R 6/19 the Enlarged Board of Appeal held that the basis for an opposition division's discretion to admit or not admit claim requests was Art. 123(1) EPC. Analysing the wording of this article, the Enlarged Board observed that the first sentence states the general possibility to carry out amendments in patent applications and in patents, but only in accordance with the provisions of the Implementing Regulations (R. 81(3) EPC for opposition proceedings). It also noted that the second sentence of Art. 123(1) EPC explicitly provides applicants with a right to at least one opportunity to amend an application and remarked that, were the first sentence of Art. 123(1) EPC to mean that the patent proprietor or applicant always has the right to amend their patent or application, the second sentence of Art. 123(1) EPC would be redundant. The Enlarged Board pointed out that the right, found in the second sentence of Art. 123(1) EPC, to at least one opportunity to amend, does not extend to a patent proprietor in opposition proceedings, where the opposition division has the discretion, given in the first sentence of Art. 123(1) EPC, not to admit such requests. In such proceedings an opportunity to amend is to be given only where necessary (R. 81(3) EPC). The Enlarged Board saw no need to answer the question whether Art. 114(2) EPC, too, provides a basis for refusing requests.