With the entry into force of the EPC 2000, Art. 105a EPC has been introduced, pursuant to which a European patent may be revoked or limited at the request of the proprietor. Limitation can be achieved by an amendment of the claims. The effect of a successful limitation or revocation is that the patent is limited or revoked ab initio (Art. 68 EPC) and in respect of all the Contracting States in which it has been granted. It takes effect on the date on which the mention of the decision to limit or revoke is published in the European Patent Bulletin (Art. 105b(3) EPC, T 646/08, T 2177/12). The nature of this procedure, which is ex parte, lies somewhere between the examination and opposition proceedings (G 3/14, OJ 2015, A102).

There is no time limit as to when the request for limitation/revocation can be made. However, it is a precondition that no opposition proceedings (including opposition appeal proceedings) in respect of the patent are pending (Art. 105a(2) EPC). If they are, then the request is deemed not to have been filed (R. 93(1) EPC). If limitation proceedings are pending at the time of the filing of an opposition, the limitation proceedings are terminated (R. 93(2) EPC). If a patentee wishes to revoke his patent whilst opposition proceedings are ongoing, he may do so but not by using the procedure set out in Art. 105a EPC-Art. 105c EPC (see in this chapter IV.C.5.2.). If he wishes to limit his patent, he may be able to do so by amending it in the course of the opposition and opposition appeal procedure.

The decision as to whether a request for limitation or revocation under Art. 105a EPC is granted is taken by the examining division (R. 91 EPC). If the request is admissible, the examining division examines whether the amended claims constitute a limitation of the claims of the European patent as granted or amended, and whether they comply with Art. 84, 123(2) and 123(3) EPC (R. 95(2) EPC). No examination of the claims with regard to Art. 52-57 EPC is foreseen. The decision of the examining division is appealable before the technical boards of appeal. As at 31 March 2019 no decision of the boards of appeal concerns an appeal against such a decision of the examining division.