European Patent Opposition Proceedings

IP Brochure

Any European patent newly granted by an Examining Division of the European Patent Office (EPO) can be challenged to obtain its revocation, or at least its limitation. To this end, the European Patent Convention provides the possibility to file an opposition against the patent. This leads to opposition proceedings, a special inter partes procedure before the EPO, the main aspects of which are presented in this brochure.

1. Initiating opposition proceedings

Opposition proceedings may be initiated against a European patent within nine months after publication of the mention of its grant. Since no legal interest of the opponent has to be proven, an opposition may be filed by any natural or legal person. Moreover, an opposition may be filed by a "straw man", i.e. a person having no real interest in the outcome of the proceedings but only acting for another – unknown – third person.