Income Tax (PAYE) and Class 1 National Insurance — calculated by the exact same engine behind ApexPayGo's real payroll runs, for England, Scotland, Wales and Northern Ireland.
This tool uses calculate_deductions() — the same function ApexPayGo uses to run real payroll — so the numbers here match what a real payslip would show for Income Tax and National Insurance. It covers Class 1 National Insurance (category A) and PAYE Income Tax only — it does not include Student Loan or Postgraduate Loan repayments, workplace pension contributions, or any other deduction that may apply to your actual pay.