Question to the HM Treasury:

To ask the Chancellor of the Exchequer, if she will make an estimate of the additional income generated per year by adding 1% to the (a) 40% and (b) 45% rate of income tax.

The number of individuals with a tax liability, set out by tax band, can be found in Table 2.1 below:

https://www.gov.uk/government/statistics/number-of-individual-income-taxpayers-by-marginal-rate-gender-and-age

HMRC does not publish estimates on the number of individuals below the Personal Allowance. However, the population statistics in the link below provide estimates of the total population, from which an assessment of non-taxpayers (those in the population but without sufficient income to pay Income Tax) can be estimated.

https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/bulletins/annualmidyearpopulationestimates/mid2023

The Exchequer Impact of changing the rates of income tax by 1 percentage point can be found in HMRC’s “Direct Effects of Illustrative Tax Changes” publication, and includes the impact of a 1p change on the higher rate (40% rate of income tax) and the impact of an increase in the additional rate (45% rate of income tax) by 1p.

https://www.gov.uk/government/statistics/direct-effects-of-illustrative-tax-changes