The contractual disclosure facility (COP 9) is one of HMRC’s most important and cost effective tools in dealing with more serious cases of tax evasion and suspected fraud. It provides taxpayers with a clearly understood way to regularise their tax affairs, whilst avoiding the costs and risks associated with criminal prosecution. However, HMRC is changing the way in which it will apply the CDF: the ‘denial with cooperation’ option is being withdrawn. The change risks reducing the effectiveness of COP 9 in a way that will be bad for taxpayers and HMRC.