This monograph challenges some key assumptions held by criminal lawyers about the actual boundaries and the proper boundaries of the criminal law. Should the criminal law be used to penalize those who fail to comply with the taxation regime? That simple question dissolves into more detailed and more complex questions— whether there should be criminal offences of noncompliance and, if so, which wrongs should be criminalized; and whether those offences should be used as the stock response to the targeted noncompliers, or whether the criminal law should be deployed as the last resort after various civil and other mechanisms. Peter Alldridge approaches these issues through rigorous analysis of the distinction between tax avoidance and tax evasion, through a sustained critique of the chaotic state of the relevant English criminal law (common law and legislation), and through a searching assessment of the machinery of prosecution. He demonstrates the importance of studying procedure, raising questions about the special powers available to those investigating tax non- compliance in relation to such issues as search, the privilege against self- incrimination, and legal professional privilege. Thus the core issues on which this monograph shines its scholarly light are not only questions of criminal law and of criminal procedure, but questions about the interaction of the two at a practical level and at a normative level.