This book is the result of the conference on 'The European Union's Struggle with Mismatches and Aggressive Tax Planning' held at the Royal Academy of Arts and Sciences in Amsterdam, the Netherlands, on 5 April 2013. The Amsterdam Centre for Tax Law (ACTL) organized the Conference in close collaboration with Ernst & Young and Stibbe. The conference aims were to inform and discuss whether and how EU and OECD policy initiatives may be successful in countering international (double) non-taxation. The conference brought together a diverse and representative array of actors involved in the fight against mismatches and aggressive tax planning, including leading officials from the European Commission, the OECD and national tax administrations, as well as expert tax practitioners and academics. In all, over 250 people from various sectors, including business and tax practitioners, academia, and members of the general public, participated in the conference.