The transfer pricing of intra-group financial transactions is a topical issue in international tax law. This book presents an in-depth analysis of how the Organisation for Economic Co-operation and Development (OECD), the European Union and eighteen selected countries apply the arm’s length principle (ALP) to thin capitalization, intra-group loans, intra-group financial guarantees and intra-group cash pooling (comparative analysis). The book also analyzes how the ALP can best be applied to these intra-group financial transactions (normative analysis).The comparative analysis provides a detailed classification of the elements which the OECD and the selected countries consider relevant in applying the ALP to intra-group financial transactions. Domestic source materials of the following countries are analyzed: Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, India, Luxembourg, The Netherlands, New Zealand, Norway, Singapore, South Africa, Sweden, Switzerland and the United Kingdom. The comparative analysis considers case law and administrative guidance up to 1 January 2020, as well as the long-awaited and important OECD guidance on intra-group financial transactions published in 2020.The normative analysis provides a conceptual analysis of the ALP in general and of the preferable application of the ALP to intra-group financial transactions. The analysis adds original ideas to the body of existing knowledge on how best to apply the ALP to intra-group financial transactions.The book is of value to academics, the OECD, tax administrations, lawmakers, courts, multinational enterprises and their tax advisors.The transfer pricing of intra-group financial transactions is a topical issue in international tax law. This book presents an in-depth analysis of how the Organisation for Economic Co-operation and Development (OECD), the European Union and eighteen selected countries apply the arm’s length principle (ALP) to thin capitalization, intra-group loans, intra-group financial guarantees and intra-group cash pooling (comparative analysis). The book also analyzes how the ALP can best be applied to these intra-group financial transactions (normative analysis).