Understand your payslip.
Most people read one number on their payslip and ignore the rest. But a wrong tax code can quietly cost you hundreds a month. Here's every line decoded — and the five-minute check worth doing.
Most people glance at one number on their payslip — what landed in the bank — and ignore the rest. Fair enough; it's a wall of codes and deductions. But five minutes understanding it is genuinely worth it, because payslips carry mistakes surprisingly often, and a wrong tax code can quietly cost you hundreds of pounds a month that you're entitled to get back.
Gross vs net — the two numbers that matter
Gross pay is what you earn before anything's taken off. Net pay (or ‘take-home’) is what actually reaches you after deductions. The gap between them is tax, National Insurance, pension and anything else. Knowing both matters: gross is what you negotiate on and what lenders assess; net is what you actually live on.
Your tax code — the bit worth checking
Your tax code tells your employer how much you can earn tax-free before Income Tax kicks in. For most people in 2026 it's 1257L — the ‘1257’ reflects the £12,570 personal allowance. If yours looks very different, it's worth understanding why.
A code with W1, M1 or X on the end is ‘emergency tax’ — common after starting a new job — and can mean you're overpaying. A BR code taxes everything at basic rate with no tax-free allowance. If you see these and they don't look right, contact HMRC: a wrong code is one of the few money problems where a phone call can put hundreds of pounds back in your pocket, sometimes backdated.
Income Tax, in bands
You're not taxed at one flat rate — it steps up as you earn more (2026 figures, England):
- First £12,570 — 0% (your personal allowance)
- £12,571 to £50,270 — 20% (basic rate)
- £50,271 to £125,140 — 40% (higher rate)
- Over £125,140 — 45% (additional rate)
Only the money in each band is taxed at that rate — a common misunderstanding is thinking a pay rise into the 40% band taxes your whole salary at 40%. It doesn't; just the slice above the threshold.
National Insurance and the rest
National Insurance is a second deduction, paid on earnings above a threshold, and it's what builds your entitlement to the State Pension and some benefits. Your payslip will also usually show your pension contribution — and if there's an employer contribution alongside it, that's free money you'd be daft to opt out of. Check the pension line is actually there; auto-enrolment should mean it is.
Once a year, glance at your payslip and ask: is my tax code right, is my pension contribution showing, and does the take-home look about right for my salary? Occasionally that quick check uncovers months of overpaid tax you can reclaim.
You don't need to become a payroll expert. But knowing what each line means — and spotting when the tax code looks wrong — is one of those small pieces of financial literacy that occasionally pays for itself many times over.
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