Payslip checker: is my payslip right?
Enter what your payslip says and this works out what each line should be for 2026/27, then tells you where it differs and why. On £36,000 paid monthly, a standard 1257L code should deduct £390.50 income tax and £156.20 National Insurance, leaving £2,453.30.
Calculator
Payslip checker
1. Your details
Copy these from the top of the payslip, not from your contract.
2. What the payslip says
The deduction figures for this period only, not the year-to-date column.
Nothing you type here leaves your browser. There is no server to send it to: this page is static and the sums run on your device.
What it should say
On £3,000.00 monthly, which annualises to £36,000 on tax code 1257L.
| Line | Should be | Yours says | Difference |
|---|---|---|---|
| Income tax | £390.50 | — | — |
| National Insurance | £156.20 | — | — |
| Student loan | £0.00 | — | — |
| Take-home pay | £2,453.30 | — | — |
Fill in the deduction figures above and each line will be compared.
A difference is not proof of an error. PAYE is cumulative: it spreads your allowance and bands across the year and corrects itself as it goes. A period after a pay rise, a bonus, a mid-year start or a tax code change will legitimately differ from the annualised figure above, and usually settles over the following months. What this page is good at is finding a difference that repeats every period, which is the kind that does not fix itself.
Assumes the code as entered, no benefits in kind and no other income. Rates from HMRC for 2026/27, checked 28 August 2026.
The four errors worth looking for
Payroll mistakes are rarely dramatic. They are usually one wrong setting that repeats quietly every month, which is why they can run for a year before anyone notices.
- An emergency or month-1 tax code. A code ending W1, M1 or X taxes each period in isolation instead of cumulatively. It is common after starting a job without a P45, and it usually over-deducts. Decode your code.
- The wrong student loan plan. The thresholds differ by thousands of pounds, so the wrong plan produces a figure that looks plausible and is not. Check all five plans.
- The wrong National Insurance category. The letter on your payslip decides the rate. Category C pays nothing, B pays a reduced rate, and J defers because you are paying on another job. See how NI is worked out.
- The pension taken the wrong way. Salary sacrifice, net pay and relief at source produce three different take-home figures from the same contribution. If yours changed and your net pay moved more than you expected, this is usually why. Compare the three.
Why a difference is often not an error
PAYE is cumulative. It spreads your personal allowance and your rate bands evenly across the tax year, and every payday it recalculates the whole year to date. That design corrects itself: a month where you were over-taxed is followed by months where you are under-taxed, until the year balances. So a single payslip that differs from an annualised figure is normal after a pay rise, a bonus, a mid-year start or a tax code change. What is not normal is the same gap, in the same direction, every period. That is the pattern this page is built to find.
Checking a whole year with your P60
One payslip only ever shows one period. Your P60, issued by every employer after 5 April, shows the totals for the whole tax year: gross pay, income tax, National Insurance and the final tax code used. That is the document to check if you suspect a problem ran all year, because it is cumulative and a single payslip is not. Put the P60 gross figure into the calculator above and the tax it returns should match the P60 to within a few pounds. A gap of hundreds usually means the tax code was wrong for most of the year. If you left a job mid-year your P45 does the same job for the part of the year you worked there, and both figures matter because the new employer's PAYE is built on them.
If it is wrong
Tax code problems are HMRC's to fix, not your employer's: your employer must use the code they are given. Check your code in your Personal Tax Account and contact HMRC to correct it, and any overpayment usually comes back automatically through PAYE once the code changes. Everything else, wrong hours, the wrong pension rate, an unexplained deduction, is payroll's. Ask in writing for a breakdown of every deduction and keep the reply. If you think you have overpaid across a whole year, the tax rebate calculator estimates what is due.
Figures checked 28 August 2026 by Hadi against HMRC rates for 2026/27. Method on the about page. This is an estimate, not tax advice, and it does not replace advice from your payroll department or HMRC.
How to use the payslip checker
- 1
Enter your gross pay for the period exactly as it appears on the payslip.
- 2
Enter the tax, National Insurance, pension and student loan lines from the same payslip.
- 3
Add your tax code and pay frequency.
- 4
Read the check: each line is recalculated and anything that does not match is flagged.
When should you use the payslip checker?
Use it when a payslip looks wrong, when you start a job, or once a year as a matter of habit, since errors repeat silently.
Your take-home changed unexpectedly
A payroll error repeats every month until somebody notices it.
You started a new job
The first payslip is where emergency codes and missing P45s show up.
You are on an emergency code
Codes ending W1, M1 or X tax each period in isolation and usually take too much.
Your pension line looks wrong
The three pension arrangements produce different figures on the same contribution.
Where to go next
- Tax code checkerTo decode the tax code on the payslip.Open
- National Insurance calculatorTo check the NI line on its own.Open
- Tax rebate calculatorTo claim back anything that was overpaid.Open
All 51 calculators share one tested engine, so a figure from the payslip checker agrees with every other page here. See the full calculator index or the pay and tax guides.