In G 3/99 (OJ 2002, 347), the Enlarged Board of Appeal held that an opposition filed in common by two or more persons, which otherwise met the requirements of Art. 99 EPC and R. 3 EPC (former R. 1 EPC 1973) and R. 76 EPC (former R. 55 EPC 1973), was admissible on payment of a single opposition fee. The payment of the opposition fee was linked to the filing of an opposition and not to the number of persons who filed the opposition. There was no procedural difference with respect to an opposition filed by a single natural person, by a single legal person or by a single body equivalent to a legal person by virtue of the law governing it.
With respect to the interpretation of the words "any person" in Art. 99(1) EPC, the Enlarged Board of Appeal held that, as regards an opposition filed in common by a plurality of persons, the common opponents had to be either a natural person, a legal person, a body equivalent to a legal person by virtue of the law governing it or a combination thereof.