This paper forms part of a series of nine studies on the role of the European Union in international economic fora, prepared by Policy Department A at the request of the Committee on Economic and Monetary Affairs of the European Parliament. It provides factual background information about the G20, the EU’s role and representation therein, its accountability as well as the coordination and impact thereof. The G20 has played a key role in measures taken to overcome the economic and financial crisis and promoted rules to prevent a repetition of such a crisis. The high compliance rate of the EU in implementing these commitments highlights the importance of the legally non-binding G20 commitments. Yet, the G20 is an informal international body where executives from officials’ up to leaders’ level meet. As a body G20 lacks meaningful accountability mechanisms. Moreover the EU can hardly be held to account for its action at the G20 level. This study provides a thorough analysis of the G20 and EU’s action at the G20 level. It sets out the EU legal framework for the participation of the EU and its Member States in the G20. In applying a two-tier accountability framework it identifies accountability gaps and concludes with policy recommendations.