This book explores the two main mechanisms available for the recovery of overpaid tax: statutory schemes and claims in unjust enrichment. These two types of claim sit together uncomfortably, as they have different requirements and defences, whilst also overlapping. The courts have considered questions as to when one should apply rather than the other, but the answers have resulted in more questions than solutions. This book will explore the similarities and differences between the regimes and consider why the differences between them are important. It will then consider which areas can be reconciled and where they cannot be reconciled, how the law should move forward. Community law has also played a major role in the development of this area, as evidenced in a number of recent and ongoing cases. The book will consider the Community law impact on the recovery of overpaid tax and the extent to which the current recovery methods available in the UK can deal with the requirements of Community law. One further mechanism to recover overpaid tax, in relation to trustees further to the case of Hastings-Bass will also be considered, in particular the extent to which they should retain a privileged position in their ability to recover tax considered overpaid. Whilst the focus of the book will be on recovery regimes in the UK, the approaches of other countries, in particular Australia and Canada which have the closest common law regimes, will also be considered for comparison and to see if guidance can be gleaned on the direction the law in the UK should take.