A "straw man" enables a party to oppose a European patent while maintaining anonymity.

When a European patent is granted, there is a nine-month window during which it may be opposed – in an attempt either to revoke the patent or to restrict its scope of protection. The patent can be opposed by any person (legal or natural), other than the original patent proprietor.

In Europe, an opposition may be filed by a "straw man" – that is, a person who files an opposition in their own name while acting for another that remains anonymous. The European Patent Office accepts such oppositions, provided that the use of a straw man does not circumvent the law by abuse of process.

In two decisions,(1) the Enlarged Board of Appeal clarified that such a circumvention of the law arises, for example, if the opponent is acting on behalf of the patent proprietor.

However, the opposition would not be considered to be inadmissible purely because a professional representative is acting in their own name on behalf of a client if:

  • an opponent who resides or has a principal place of business in a contracting state of the European Patent Convention acts on behalf of a third party who does not meet this requirement; or
  • the straw man opponent confirms that they are acting for a third party.

In any case, the principle of the free evaluation of evidence applies. The burden of proof lies with the person alleging that the opposition is inadmissible, and this proof must be clear and unequivocal.

It is important to note that the possibility to file an opposition in the name of a straw man is not acceptable before all national and regional offices.

For further information on this topic please contact Stijn Lagaert at GEVERS by telephone (+32 2 715 3711) or email ([email protected]). The GEVERS website can be accessed at www.gevers.eu.


(1) G3/97 and G4/97.