HMRC PUBLISHES METHODOLOGY FOR INCOME TAX LIABILITY ESTIMATES

Her Majesty's Revenue and Customs has published an explanation of how it estimates Income Tax liabilities at the individual level. The estimates are derived from the Survey of Personal Incomes, which collects data on Income Tax payer incomes and circumstances. HMRC distinguishes between liabilities—amounts of tax due on incomes in a given tax year—and receipts, which represent amounts actually paid and collected in that same year. The two figures do not match because of payment delays, particularly through Self Assessment.

HMRC produces breakdowns of Income Tax payers and liabilities across several variables: age, sex, country, Government Office Region, marginal tax rate, income source and tax band. The organisation notes that analysing Income Tax receipts by individual characteristics such as marginal rate, age or sex is not possible given how the tax is collected. However, such analyses can be conducted through modelling Income Tax liabilities based on a representative sample of individuals drawn from administrative data. HMRC also publishes separate detailed statistics on personal incomes.

The distinction between liabilities and receipts reflects the mechanics of Income Tax collection, which introduce timing gaps between when tax is assessed and when it is paid. Users requiring information about actual amounts collected by HMRC in any given tax year, or details of collection methods, are directed to HMRC's separate statistics on Income Tax receipts. The published methodology allows researchers and analysts to understand how the liability figures are constructed and their limitations.