This book serves as an introduction to the current EU Value Added Tax system. It provides a concise overview of the working of EU VAT and the concepts and rationale behind it. The goal of this book is to enable the reader obtaining a basic knowledge of the EU VAT system, or to refresh his or hers memory within a day's work.Hence, this book is titled: 'VAT in a Day'. Even though the book covers all aspects of the EU VAT system, some elements are discussed in more details than others. Didactically sound choices were made as regards the depth at which the various subjects in this book are discussed.Nevertheless, the book provides an account of the key provisions in the VAT Directive and the key case law of the Court of Justice of the European Union in the field of VAT.