The increased shares of renewable energy, combined with the rise in distributed generation are profoundly impacting electricity markets and the demand for system flexibility and business models of traditional utilities and distribution companies. This requires a rethinking of the way power sector markets are designed and operated as well as a timely and efficient adaptation of traditional market and operational mechanisms. The recent created clean energy legislation requires that Electricity Markets are created with “active customers/consumers and citizens” and “energy communities”. This new legislation asks for enhanced roles of DSOs and TSOs, particularly for a better coordination among stakeholders, procurement of ancillary services, flexibility, data management and integration of Electric Vehicles and must adapt network access and congestion tariffs & charges (flexibility). Markets must encourage the development of more flexible generation and demand and the elimination of obstacles to market-based pricing, remove regulatory distortions, enable scarcity pricing, interconnection, Demand Side Response and storage. Final customers must be enabled to buy electricity generation from aggregated, multiple power-generating facilities or load from multiple demand response facilities to provide joint offers on the electricity market and be jointly operated in the electricity system. Citizens must be offered competitive prices. BeFlexible aims at increasing energy system flexibility, enhancing cooperation among DSOs and TSOs and easing participation of all energy-related actors through the validation and large-scale demonstration of adapted and proven cross-sectoral services, interoperable platforms for smart grids operation developing further already demonstrated solutions and the creation of required system architecture framework to enable the creation of new business models providing additional value to meet consumers’ needs in compliance with a stable regulatory framework.