a) Payment of a single opposition fee 

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 1973 and R. 1 EPC 1973 (R. 3 EPC) and R. 55 EPC 1973 (R. 76 EPC), 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 wording "any person" in Art. 99(1) EPC 1973 and its interpretation in line with Art. 58 EPC 1973, the Enlarged Board held that, as regards an opposition filed in common by a plurality of persons, each of 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.