The right to be heard is enshrined in Art. 113 EPC and reads: "The decisions of the European Patent Office may only be based on grounds or evidence on which the parties concerned have had an opportunity to present their comments." The boards refer to this right in their case law on the duty to provide reasons under R. 111(2) EPC. The right to be heard under Art. 113(1) EPC is not just a right to present comments but also to have those comments duly considered (see, e.g. R 8/15; J 7/82, OJ 1982, 391; T 508/01; T 763/04; T 1123/04 and T 246/08). The comments presented must be considered in the ensuing decision (J 7/82, OJ 1982, 391 and T 246/08). In R 8/15 the Enlarged Board held that Art. 113(1) EPC implies that decisions of the EPO boards of appeal should adequately state the reasons on which they are based in order to show that the parties were heard. A party must be able to examine whether, in its view, the board has afforded it the right to be heard in order to be in a position to decide on whether or not to file a petition under Art. 112a(2) (c) EPC. However, Art. 113(1) EPC must be interpreted more narrowly than R. 102(g) EPC which requires a board to give reasons for its decision, but infringement thereof is not as such a ground for review. In other words: for the purpose of compliance with the right to be heard, reasons may be incomplete, but as long as they allow the conclusion to be drawn that the board, in the course of the appeal proceedings, substantively assessed a certain point arising in the procedure that it found to be relevant, there is no violation of Art. 113(1) EPC.
In T 1123/04 the board observed that the opportunity to present comments and arguments guaranteed by Art. 113(1) EPC is a fundamental principle of the examination, opposition and appeal procedures and cited the finding in T 508/01 that this is not just a right to present comments but also to have those comments duly considered.
In T 246/08 the board found that it had to be clear from the reasons that the core arguments had been addressed in substance in arriving at the decision. The decision had to show that all potentially refutative arguments adduced by a party were actually refutable. The board cited T 763/04 and said that merely repeating the parties' submissions was not enough. The board in T 1997/08 ruled that comments received in response to communications had to be taken into consideration too.
In T 420/86, for example, it was found that the opposition division had based its decision on factors on which the parties had been unable to comment because it had only emerged in the written reasons that a further document had been of central importance to the decision.