In general, the boards admit amendments filed in response to comments and objections made by the rapporteur or the other party. However, undesirable procedural delays should be avoided (see T 38/89, T 459/91, T 1059/92, T 648/96). Amended claims may be admitted into the proceedings if the introduced amendments are properly justified, e.g. have been filed as a response to objections, evidence or comments which were not part of the decision under appeal but have been raised in writing during the appeal proceedings (T 397/01, T 253/10). They must also constitute a promising attempt to counter the objection raised (T 1859/06).
In T 626/90, the board decided to admit both sets of claims submitted by the respondent in the oral proceedings. In its view, the new versions of the claims were bona fide attempts to overcome the objections raised by the appellants in connection with the question of inventive step of the claimed process, and there was no question of the appellants having been unfairly taken by surprise, because the amendments in both requests were nothing more than a limitation of the claimed subject-matter to preferred embodiments of the invention as described in the patent in suit (T 1097/99).
In T 610/94, the appellant filed a new set of claims during the oral proceedings. It argued that it had limited claim 1 in view of the prior art in D 12 which had only been cited shortly before the oral proceedings and that the new claims were a response to the deficiencies identified by the board in the annex to the summons to oral proceedings. The board decided to admit the new claims and resume the oral proceedings after an adjournment of an hour and a half. In its decision, it found that the respondent ought to have expected an amended limited claim because it itself had not cited D 12 until shortly before the oral proceedings.
In T 794/94, the board recognised that patents in the field of genetic engineering sometimes gave rise to exceptional problems which made it difficult to formulate a suitable request and therefore amounted to exceptional circumstances justifying late submission of requests designed to meet objections which had already been considered at length. However, there was no right to file an endless succession of new requests in substitution for requests found inadmissible or unallowable by the board. If it could quickly be checked that requests met the requirements of Art. 123 and Art. 84 EPC 1973 and were necessary to overcome a ground for opposition, the chances of their being accepted even at a very late stage were much improved (see also T 607/05, T 516/06).
In T 1148/97, the board took the view that late-filed claims could still be admitted if the amendments to the wording of the claims limited the scope of the subject-matter claimed to such an extent that revocation of the patent could be avoided and maintenance of the patent as amended ordered after swiftly conducted proceedings (T 710/99, T 30/03).
In T 1400/04 the late filed claims constituted reactions to objections made by the board and they were convergent clarifications of the claims which had been filed with the statement of grounds of appeal. Since in ex parte proceedings only the board had to deal with the amended case and adjournment of the oral proceedings was not necessary in view of appropriate amendments which rather reduced the complexity of the case, the board decided to admit the late filed amendments.
In T 385/06 the patent proprietor filed amendments before the final date set in the board's communication. In the judgment of the board, these amendments might be seen as a response to the board's observations relating to two grounds for opposition. Hence these amendments were allowable under R. 80 EPC, since they were occasioned by grounds for opposition invoked by the opponents. They were thus filed pursuant to directions of the board and related to the case under appeal. Since the amendments were filed two months before the oral proceedings and since the patent proprietor specified in detail the passages of the patent specification, essentially dependent claims, on which these amendments were based, the board considered that the parties and the board could reasonably be expected to deal with the amendments without adjournment of the oral proceedings.