Recommendation 21

Government’s published estimates of the costs of tax reliefs are prepared by HMRC and scrutinised by the Office for Budget Responsibility (OBR) in its role as the government’s official forecaster. Higher costs can indicate that a tax relief is working well or that it is not being used as intended.39 In 2014, we concluded that departments did not keep Parliament adequately informed of changes to the costs of tax reliefs. We also found that there was no feedback mechanism to alert Parliament if the actual cost of tax reliefs varied from HM Treasury’s forecasts, on which Parliament had based its approval of the relief. We said that in the future we would look at what the exchequer departments had done to provide proportionate feedback and analysis to Parliament each year on the costs of principal tax reliefs (those costing more than £50 million annually), including significant changes in costs.40 In their response, the exchequer departments said that the government was transparent about both the costs of existing reliefs and the costs and likely impacts of new reliefs with, for example, HMRC annually publishing information on the Exchequer cost of existing tax reliefs.41