Most legal text books and practitioners' guides focus on the impact of financial services law and regulation on individual legal entities: the application of such law and regulation on a group basis is often a cursory afterthought, or neglected altogether. This book reverses the balance. It is the first book to fully and systematically address how groups of businesses within the financial services sector are regulated. It starts with the company law and corporate insolvency law foundations on which groups are established. It then builds up through prudential and resolution-driven regulation, focusing on how such regulations apply and operate at a consolidated group and sub-group level, to the structural responses from firms and counter-responses from legislators and regulators. This new work also considers the tensions that arise from the conflicts between authorities and legal systems on a cross-border basis, and between the formal legal system and the powers and agendas of the regulators. The book covers intragroup transactions, and the role that regulation plays requiring and restricting the movement of financial resources around groups. In its final section, the book applies the principles explored in previous sections to a wide range of transaction types. It is up-to-date as at July 2019, marking the culmination of over 10 years of intense regulatory change, addresses UK ring-fencing rules and EU and US intermediate parent undertaking requirements, and considers the impact of Brexit and the EU banking reform/risk reduction package.