Income tax is a direct tax on an individual’s or certain entities’ taxable income, typically comprising employment income, self‑employed profits, pensions, rental income, savings and investment returns, and certain benefits. It is central to personal tax planning, payroll (PAYE), estate planning and disputes with HMRC or Revenue.In the UK, income tax is principally governed by the Income Tax Acts (including the Income Tax (Earnings and Pensions) Act 2003 and the Income Tax (Trading and Other Income) Act 2005) and related Finance Acts, with rates and bands set by annual Finance Acts and, for certain devolved aspects, by the Scottish Parliament and the Senedd. In Ireland, it is governed mainly by the Taxes Consolidation Act 1997 and subsequent Finance Acts.Key legal features include the concept of residence and domicile, the distinction between income and capital, source rules, reliefs, allowances, and the self‑assessment and PAYE regimes. Usage and core concepts are broadly consistent across England & Wales, Scotland, Northern Ireland and Ireland, though rates, bands, reliefs and certain administrative rules differ by jurisdiction.