This paper proposes a new concept of eGovernment Service Marketplace which aims at providing quality services by facilitating citizen and public administration interaction. The marketplace metaphor suggests the idea of a virtual common place where citizen can discover and access different available services without caring about information sources, responsibilities and composition. Moreover, administrations can take part to this market according to their technical and political capabilities. The eGovSM is based on a set of document models allowing the development of a flexible, interoperable and scalable environment: LEM (Life Event Manager) supervises interactions with citizen, DM (Document Manager) concerns the document management processes, SM (Service Manager) manages interactions with administrations, and finally UNICITIDM (UNIversal CITizen IDentifier Manager) represents the manager of unique citizen identifier.