This policy brief shows that the market access for aggregators is improving in some EU countries, while other countries are lagging. Often the regulatory frameworks are not supportive for demand response or participation of distributed renewable generation, according to the authors. However, in several EU countries, no suitable frameworks to enable participation of flexibility aggregators exist. At the same time, the emerging new technical solutions allow market actors to provide new services. The upcoming new EU electricity market directive will be an important step towards more decentralized, according to the authors; yet, harmonized electricity markets with a range of new actors and business models, and may trigger the reform of national regulatory frameworks.