HMRC and HM Treasury are insufficiently curious about the impact of some key tax reliefs on different groups. Data on who benefits from tax reliefs are crucial to understanding whether they are achieving their intended objectives and to informing decisions about which tax reliefs need amending. When he announced in the 2020 Budget that he was reforming entrepreneurs’ relief, the Chancellor stated that the relief was unfair, with nearly three quarters of the £2 billion a year cost benefiting just 5,000 individuals. However, HMRC does not collect and report data on who benefits from all major tax reliefs. It does not, for example, distinguish between subsidising new luxury properties or affordable homes that are built as a result of the £15 billion VAT relief on the construction of new dwellings, and subsequently does not know who benefits from the tax relief. The data HMRC publishes on who receives pensions reliefs is limited and we are concerned that some groups are not benefiting from tax relief on their pension when they should. For example, around 1.75 million low-paid and part-time workers earning less than the personal allowance of whom around three quarters are women, will not be getting tax relief on their pension contributions after being auto-enrolled into employer pensions. Recommendation: HMRC should assess the groups and sectors benefiting from all significant reliefs and publicly report the results during 2021. For pension reliefs, HMRC should publish data showing who is benefiting, split by: income; groups with protected characteristics such as gender, age, ethnicity; people working in the public and private sectors; and people in defined contribution and defined benefit schemes.