This book presents an analysis of the concept of the administrative act and its classification as ‘foreign’, and studies the administrative procedure for adopting administrative acts in a range of countries in and outside Europe. While focusing on the recognition and execution of foreign administrative acts, the book examines the validity, efficacy and enforceability of foreign administrative acts at national level. The book starts with a general analysis of the issue, offering general conclusions about the experiences in different countries. It then analyses the aforementioned themes from the perspective of the domestic law of different European nations and a number of international organisations (European Union, MERCOSUR, and Andean Community). In addition, the book studies the role of the European Union in the progress towards the recognition and execution of foreign administrative acts, where the principle of mutual recognition plays a vital part. Finally, the book analyses the international conventions on the recognition and execution of administrative acts and on the legalisation of public documents.