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).

The board in T 2227/12 stated in its catchword: where only objections under Art. 123(2) and 84 EPC have been addressed in the contested decision and in the appeal proceedings, the board, in deciding whether to admit a request filed at the oral proceedings, need examine only whether it is prima facie allowable in view of those objections and need not examine its prima facie allowability under Art. 52(1), 54 and 56 EPC.

In the cases below, the amended requests were admitted:

In T 93/11 the amendments were the direct result of the board's communication. Furthermore, they also overcame the formal objections of the board, which was procedurally expedient. Finally, they simply narrowed down the subject-matter claimed to the core of the invention. The board further considered that there was no general prohibition on reacting to a board's communication by submitting new requests, let alone when these took account of all the objections raised or repeated therein. Furthermore, the number of issues to be discussed at the oral proceedings was substantially reduced.

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 (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 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.

In T 610/94 too, the board admitted sets of claims filed during the oral proceedings because they had been limited and took account of the deficiencies it had identified. In T 626/90, 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). Likewise, in the ex parte proceedings T 1400/04, the amended claims were admitted because the oral proceedings did not need to be adjourned.

In T 407/14, the additional feature in claim 1 of the main request amounted to a clear limitation of the claimed subject-matter. The board held it to be a legitimate response on the part of the appellant to the preliminary opinion of a lack of inventive step.

In T 442/12 the late-filed request was admitted because it was prima facie a promising attempt to overcome all the objections set out in the board's communication and detailed supporting reasons had been given.