During the last years worldwide many initiatives come up to improve the quality of public services information. In Europe this process is mainly initiated by the European service directive. Germany actually has started a special project called D115, which shall provide a simple, quick and efficient access to public service information German-wide by using a single phone number 115. One technical problem in the context of D115 is the intelligent and quick routing of incoming calls to the enquiry offices, another is the technical integration and maintenance of the existing public service information repositories and a special semantic problem is the customer-orientated identification, description and the functional exchange of this knowledge between the participating organizations and public service centres. The general goal of this project is building up a virtual network of service centres with one face to the customer like citizens and enterprises, which ensures valid and quick access to information about all available public services in Germany. A crucial prerequisite to reach this goal is the semantic integration of the distributed knowledge about public services that can be found in different locations, organizations and formats mostly formulated in an inconsistent and sometimes misunderstandable manner. Given the multitude and diversity of public authorities, e. g. there are more than 12,000 municipalities in Germany, an intelligent and flexible solution to integrate these different service repositories is needed. During the last years different semantic approaches in general based on ontologies were developed to integrate distributed information about public services. Theses approaches mainly focus on formal and structural aspects of public service descriptions, i.e. which attributes or characteristics should be used to describe a public service. But concepts and solutions for an effective and valid harmonizing of the semantic differences are not available or address this issueonly partially. In this paper existing approaches for describing public services are examined in regard to the requirements and constraints of public service centres and in the context of the project D115. Furthermore a new approach to define and build of a taxonomy of public services to support the process of providing information in public service centres is proposed. This approach is based on results of a research project of the University of Duisburg-Essen within the context of the D115 initiative in cooperation with the service centres of several municipalities in North Rhine-Westphalia. The project was designed to gather the requirements for a classification system of public services from the perspective of public service centres as well as to verify the feasibility of this approach in the service centre praxis.