Recommendation 2

HMRC does not know the relative size of tax gaps in the four nations of the UK or across different industries. HMRC already publishes breakdowns of the tax gap by taxpayer group, tax type and behaviour. However, HMRC does not calculate or publish estimates of the tax gap for each of the four nations of the UK. We recognise the difficulties in doing so but HMRC ought to be able to produce reasonable estimates for the tax gaps in the four nations of the UK, particularly since the devolution of Income Tax powers to Scotland from 2016–17, and Wales from 2019–