Article gives e – service definition and shows some practical examples. Restrictions, which dwarf e – services, are also enumerated. There is look at possibilities of the service architecture, and also description of mine service architecture components: authentication, authorization, integration with functional and financing systems, and management subsystem. Conditions of XML WEB services development are given – cohesion and coupling of service. Conditions are necessary to reduce labor-intensity and increase reusability. Solution of client authentication and authorization is described. Possibilities of XML WEB service functionality in e – services are handled as the vision of future.