Payslip Explained: Understanding Tax and National Insurance in the UK

Opening a payslip for the first time can feel like reading a foreign language — gross pay, tax code, National Insurance, pension contributions, and a "net pay" figure that never seems to match what you expected. Here's the short version.

Gross vs net pay. Gross pay is everything you earn before deductions. Net pay (or "take-home pay") is what actually lands in your bank account after tax, National Insurance, and any pension contributions or student loan repayments come out.

Income Tax. Most people get a tax-free Personal Allowance each year — you don't pay any Income Tax on earnings up to that threshold. Above it, tax is charged in bands: a basic rate, a higher rate, and an additional rate for very high earners. Your tax code (shown on your payslip) tells your employer how much of your pay is tax-free.

National Insurance (NI). NI is a separate deduction that funds the State Pension and certain benefits. Like Income Tax, it only kicks in once you earn above a threshold, and the rate is a percentage of earnings above that point.

Workplace pension. If you're enrolled in your employer's pension scheme (most employees are, automatically), you'll see a pension deduction too — and your employer will usually add their own contribution on top, which is effectively free money.

Why it's worth checking. Tax codes and payslips do contain errors. If your tax code looks off, or a deduction appears you don't recognise, it's worth querying it with your payroll team or HMRC directly — over- or under-paying tax is more common than people think.

This is general information, not financial advice. For anything specific to your circumstances, check gov.uk or speak to an accountant.