R. (Hely-Hutchinson) v HMRC: fairness in tax law and revenue guidance

From the vantage point of tax collection, fairness has long been recognised as a public law consideration which prevents HMRC from doggedly pursuing all tax that is due. How exactly the duty to act fairly towards taxpayers interacts with HMRC’s primary duty to collect and manage taxes came to be considered in a recent judicial review case before Whipple J in the High Court, namely R. (on the application of Hely-Hutchinson) v HMRC. The Court was further required to assess the effect of this interrelationship with regard to HMRC guidance. In particular, the assessment concerned how this interrelationship constrains HMRC from retroactively withdrawing treatment prescribed in a publication which is based upon an incorrect interpretation of the relevant law.