Finance Act 2007 conferred new, uniform powers of investigation on HMRC, following a consultation process. The powers relate to situations where HMRC suspect criminal activity, and allow HMRC officers to apply for production orders and entry and search warrants, to detain, question and fingerprint individuals (including, in certain circumstances, to take them to HMRC offices), and ultimately to arrest suspects. This article discusses these powers and how they might be applied, highlighting some of the problems that not only individuals against whom the powers are applied but also HMRC may come across in practice.