Since the decision of the House of Lords in Woolwich Equitable Building Society v Inland Revenue Commissioners [1993] AC 70, the law governing claims for restitution of overpaid tax has experienced rapid and profound evolution. This has been so not only in England, but also elsewhere in the common law world as well as on the European plane. The essays in this collection consider the new landscape, and explore from various doctrinal and national perspectives the issues that have confronted, and continue to confront, the courts.