This paper describes the architecture of the FLEXICIENCY project, looking at functional and nonfunctional requirements, for B2B interactions (mainly between DSO and Data Requester such as an Energy Service Operator ESO. It includes a Market Place as a contact point and IT innovative platform to be developed. A common architecture framework is defined and requirements are listed for data and service exchange at EU level, addressing data privacy and interoperability, among regulated and unregulated energy players.