Why check your payslip?
Wrong tax codes and payroll errors are common. A quick sanity check helps you spot overpayments and underpayments before they build up.
Thrivelance Tools
Payslip Checker (UK)
Check whether the income tax and National Insurance on your UK payslip look right. Enter your monthly figures and we compare them to the expected 2026/27 deductions.
Enter your monthly payslip
We annualise your gross, calculate expected deductions, and flag any gaps.
| Deduction | Your payslip | Expected | Difference |
|---|---|---|---|
| Income tax | |||
| National Insurance | |||
| Net pay |
What we compare
We recalculate income tax (PAYE) and Class 1 National Insurance from your gross and compare them to the figures on your payslip.
Reasons for a mismatch
- A non-standard tax code (not 1257L).
- Student loan, pension, or salary sacrifice.
- Bonuses or a recent pay change.
Next steps
If the gap is large and persistent, check your tax code on your payslip and contact HMRC or your payroll team.
FAQ
Common questions about this calculator.
How does the payslip checker work?
It annualises your monthly gross pay, calculates the expected income tax and National Insurance for 2026/27, and compares them with the figures on your payslip.
Why might my deductions differ from the estimate?
A non-standard tax code, pension contributions, salary sacrifice, student loan repayments, bonuses, or a recent pay change can all legitimately move your deductions.
Does it support student loans and pensions?
The checker compares income tax and National Insurance only. For pension and student loan modelling, use the full UK salary calculator.
What should I do if something looks wrong?
Check the tax code on your payslip first, then speak to your payroll team or HMRC if a large difference persists across several months.