In the Budget, it said it was to invest a further £155 million this year to recoup £2.3 billion in unpaid taxes, suggesting HMRC will have to deliver more bang for the Treasury’s buck. Aidan Sutton, partner at PWC, questioned whether there was a limitless amount of unpaid taxes that could be claimed after the successes of previous anti-avoidance campaigns: “If you do the arithmetic, this is an ambitious return for the investment.