2.4.1 General principles

Article 113(1) EPC requires that decisions may only be based on grounds or evidence on which the parties concerned have had an opportunity to present their comments.

According to the Enlarged Board (see chapter V.B.4.3.9 "Reasons for a decision allegedly surprising"), this implies that a party may not be taken by surprise by the reasons of a decision, referring to unknown grounds or evidence (R 3/13, R 5/22; see also T 1378/11). A purely subjective surprise, however, has no bearing on whether a party had an adequate opportunity to comment. "Grounds or evidence" within the meaning of Art. 113(1) EPC need not emanate from the board, it is sufficient if another party raises the objection (R 2/08). If the reason given in a decision corresponds to an argument put forward by the other party (see also T 405/94), the petitioner was aware of it and thus not taken by surprise (R 4/08, R 12/09 of 15 January 2010 date: 2010-01-15, R 8/14) unless the board clearly indicated that it regarded those arguments as not convincing (R 11/12). While Art. 113(1) EPC presupposes that the opportunity to present comments must not be of a purely theoretical nature, it does not release a party from its obligation to present its response promptly (R 24/22).

Although parties may not be taken by surprise by the reasons for a decision, it is also settled case law of the Enlarged Board under Art. 112a EPC that a board of appeal is not required to provide the parties in advance with all foreseeable arguments in favour of or against a request. In other words, parties are not entitled to advance indications of all reasons for a decision in detail (see chapter V.B.4.3.5 "No obligation to provide detailed reasons for a decision in advance"). In T 1634/10, T 2405/10, T 1378/11 and T 1090/18 the boards explicitly applied this case law of the Enlarged Board in relation to Art. 112a EPC to first-instance proceedings.

In T 996/09 the board held that the right to be heard was a fundamental guarantor for the parties that proceedings before the EPO would be conducted fairly and openly (with further reference to J 20/85 and J 3/90) and was intended to ensure that the parties to the proceedings were not taken by surprise by grounds mentioned in an adverse decision (following T 669/90, T 892/92, T 594/00 and T 343/01; see also T 197/88, T 220/93). In T 435/07 the board held that the grounds on which a decision were based had to be communicated to the applicants in such a way that they were put in the position to defend their rights. An objection against the grant of a patent had to be raised in such a way that the applicants were able to understand its factual basis and to react accordingly without first having to guess what the examining division might have had in mind. According to the board in T 898/21, the crucial factor was not whether the department of first instance would have come to the same conclusion after hearing the parties on a specific objection, but whether the parties were given an opportunity to comment on that objection.

In T 1065/16, lack of reproducibility as a ground for opposition had not been a subject of the opposition proceedings until the oral proceedings. It therefore amounted to a fresh ground for opposition and its introduction came as a surprise. In its summons, the opposition division had expressly stated that only novelty and the inventive step of claim 1's subject-matter were to be examined. As the patent proprietor had not been given sufficient opportunity to comment on this new ground for opposition, the opposition division had infringed Art. 113(1) EPC and thus committed a substantial procedural violation.

In T 2351/16 the board found that the examining division had issued a decision of refusal after only one communication under Art. 94(3) EPC as such did not constitute a violation of the appellant's right to be heard (see also chapter IV.B.2.3. "Refusal after a single communication"). However, in its decision the examining division had raised (for the first time) an additional argument in support of the division's objection, following the applicant's reply to the Art. 94(3) EPC communication. This constituted a violation of the applicant's right to be heard and, therefore, a substantial procedural violation.

In T 2054/19 the Art. 94(3) EPC communication had concerned a different set of claims compared to the one underlying the decision by the examining division to refuse the application. The applicant had neither been made aware that the examining division had considered the scope of claim 1 before it to be identical to the scope of claim 1 as originally filed and objected to in the European search report, nor of the fact that it had relied on the search opinion. The board held that in this case the immediate refusal of the application following the Art. 94(3) EPC communication amounted to a violation of the right to be heard.

In T 505/20 the board held that the opposition division’s failure to consider the valid claim as submitted at the oral proceedings had resulted, among others, in the violation of the appellants’ right to be heard. The opposition division had decided that the patent could be maintained in amended form on the basis of this claim request for reasons that the appellants had not been given the opportunity to comment on. This constituted a substantial procedural violation.

In T 1198/20 the board confirmed that Art. 101(1), second sentence, EPC did not require the opposition division to send a communication with a preliminary opinion before giving its decision. It merely required the opposition division to invite the parties to file observations on communications from another party or issued by itself "as often as necessary" in order to satisfy the right to be heard under Art. 113(1) EPC. The board found that the opposition division had based its decision on the grounds and evidence set out in the notice of opposition, i.e. on grounds and evidence on which the patent proprietor had already had an opportunity to present its comments. The board, thus, considered the requirements of Art. 113(1) EPC fulfilled.

In T 1976/22 the board found that the appellant's rights under Art. 113 EPC were fully respected by the board’s immediate decision in writing since it had been issued on the basis of the appealed decision and the statement of grounds of appeal.