Allowances from IFS Fiscal Facts income tax table. Historical allowances adjusted for inflation using the Consumer Prices Index (ONS series D7BT). Average earnings figure is 52 x average weekly earnings (AWE; ONS series KA46 and MD9M). Forecasts for CPI and average earnings from Office for Budget Responsibility, https://obr.uk/efo/economic-and-fiscal-outlook-march-2023/.
Lower headline tax rates on self-employment than on employment aren’t justified by differences in benefits or employment rights, and are poorly targeted at improving investment incentives.