This paper describes the concepts and system approach of FAMS, Flexible Agency for Collective Demand Responsive Mobility Services, a European project founded by the EU-IST Programme and operating in the Florence Metropolitan area. The objective of FAMS Project is to scale up the technology, service and business models currently adopted in demand responsive transport (DRT) and support the evolution from single DRT applications to the concept of an agency for such services. State-of-the-art DRT technology-i.e. booking and reservation systems, route and service planning systems, communication services, service management services, service and customer repositories, etc.-will be further extended and adapted to work within an innovative e-Business infrastructure in order to to achieve networking of the different transport operators involved in Transport services and to allow sharing of information and service interoperability among them. This will ultimately allow different transport operators to cooperate and the overall transport system to work as a virtual, flexible organization. FAMS will implement and trial the concept in the Tuscany region (Italy) and the Angus region (UK).