In the context of the consultation process launched by the Commission communication on social services of general interest (SSGIs) of April 20061, the Commission received a number of questions concerning the application of the European Union rules on state aid, public procurement, and the internal market to services of general economic interest (SGEIs), and in particular to SSGIs. The purpose of this document is to provide answers to the questions concerning the application of state aid rules to SSGIs and SGEIs. The document is also intended to provide answers to the questions concerning the application of the rules on public procurement to SSGIs in order to clarify the obligations on public authorities when they buy social services in the market. Finally, the document provides answers concerning the application of the Treaty rules on the freedom to provide services and the freedom of establishment (hereinafter: 'internal market rules') to SSGIs and the application of the rules in the Services Directive to SSGIs.