Paye was introduced at the outbreak of the Second World War due to the financial strain that WWW2 put on the country. Finance being ‘the fourth arm of defence. Anyone earning over £100 was issued a Tax Code, the system added two million tax payers to the system. Personal Tax was 29%, with a 48% supertax for incomes over £20,000.
An Excess Profits Tax was introduced for businesses, taxing the extra profits initially at 60% then 100%. 100%!
In 1939 tax collected was £400m, in 1944 it was £1,400m!
In an extraordinary arrangement a portion of the Supertax and Excess Profit Tax were repaid to taxpayers and business post-war (who had kept their post war credit certificates), aimed at boosting reconstruction.