A client data model for social welfare was gradually developed in the National Project of IT in Social Services in Finland. The client data model describes the nationally uniformed data structures and relationships between the data elements needed in production of social services. It contains the structures of social care client records, unique core components and distinct classifications. The modeling method guaranteed the coverage, integrity, flexibility and device independency of the model. The model is maintained and developed by the National Institute for Health and Welfare (THL) together with the social workers and other experts of social welfare. It forms the basis of the electronic information management of the social services. Implementation of the data model in information systems enables the availability of the client data where and when ever a client has to be helped.