Why Your Payslip Does Not Match Any Calculator
Nine reasons, in order of how often they are the answer. Most of them are not mistakes.
Nine causes, in rough order of how often they turn out to be the answer. Only two of them are actually errors, which is the reassuring part.
The nine reasons
1. An emergency or Week 1 / Month 1 code. Look for W1, M1 or X. Common on a new job and self-correcting.
2. A mid-year pay change. Cumulative PAYE spreads the correction rather than applying it cleanly.
3. A bonus or back pay month. PAYE annualises the month and over-deducts.
4. A payrolled benefit. A company car or medical cover raises taxable pay without raising gross pay.
5. Salary sacrifice. Your payslip gross is below your contractual salary.
6. An unexpected student loan plan. Plan 5 became the default for new starters who do not state a plan from 2026/27.
7. A relief at source pension. Taxable pay is not reduced, so tax looks higher.
8. National Insurance on an uneven month. Worked out per period, so overtime concentrated in one month costs more.
9. An actual coding error. Last on the list for a reason.
What to check first
Your tax code and whether it carries W1, M1 or X. Your taxable gross against your contractual gross. Your year-to-date figures, which should climb smoothly. And whether your pension line sits before or after the tax line. The tax code checker will tell you what your code is doing.
Questions people actually ask
Why does my payslip not match online calculators?
Should I contact payroll or HMRC?
The numbers this sits on
| Salary | Income tax | National Insurance | Take-home | A month | Effective rate |
|---|---|---|---|---|---|
| £25,000 | £2,486 | £994 | £21,520 | £1,793 | 13.9% |
| £35,000 | £4,486 | £1,794 | £28,720 | £2,393 | 17.9% |
| £45,000 | £6,486 | £2,594 | £35,920 | £2,993 | 20.2% |
| £60,000 | £11,432 | £3,210 | £45,358 | £3,780 | 24.4% |
| £85,000 | £21,432 | £3,710 | £59,858 | £4,988 | 29.6% |
| £110,000 | £33,432 | £4,210 | £72,358 | £6,030 | 34.2% |
Every figure in that table is computed from the published 2026/27 rates by the same engine that runs the calculators on this site, so a number in an article and a number in a calculator can never drift apart. National Insurance uses the statutory period thresholds real payroll uses, which is why these figures reconcile with a payslip rather than nearly reconciling with one.
| Salary | England, Wales, NI | Scotland | With a Plan 2 loan | Keep from the next £1,000 |
|---|---|---|---|---|
| £28,000 | 28.0% | 28.0% | 28.0% | £720.00 |
| £40,000 | 28.0% | 29.0% | 37.6% | £720.00 |
| £52,000 | 42.0% | 44.0% | 51.6% | £580.00 |
| £65,000 | 42.0% | 44.0% | 50.4% | £580.00 |
| £105,000 | 62.0% | 69.5% | 70.4% | £380.00 |
| £130,000 | 47.0% | 50.0% | 56.6% | £530.00 |
Work it out for yourself
- Take-home pay calculatorThe main calculator, all four UK nations.
- Pay rise calculatorWhat a raise really adds.
- Salary sacrificeWhat you are trading.
- Tax code checkerWhat each letter and prefix does.
Figures on this page are for the 2026/27 tax year (6 April 2026 to 5 April 2027) and were last checked on 29 August 2026. Every rate we use is listed on the sources page.