Free tax refund calculator for overpayment signals.
Use this free calculator as a calm first-check when you think too much Income Tax may have been paid, without presenting it as a guaranteed HMRC outcome.
Calculator
Enter details. Read the result.
Overpayment check
Check whether paid Income Tax looks high enough to review
This tool compares approximate expected Income Tax with the tax already paid and helps show whether there is a refund-style signal.
Best use
First-check overpayment read
Best next step
Tax code + payslip check
Step 1
Enter salary and tax paid
Use an annual salary estimate and the Income Tax already paid if you want a quick refund-style signal.
What usually causes refund suspicion
Emergency tax, tax code issues, job changes, leaving work mid-year, or periods where payroll deducted too much too early.
Step 2
Read the refund-style signal
This is designed to show whether paid tax looks high enough to justify deeper checking.
Interpretation
There may be a moderate overpayment signal worth reviewing
The gap is noticeable enough that a tax-code issue, job change, emergency tax period, or payroll adjustment may be worth reviewing.
Expected tax
£4,486
Tax paid
£5,200
Possible refund signal
£714
Best next move
A refund signal is strongest when it is supported by a tax-code issue, unusual payslip pattern, or mid-year employment change rather than a single number alone.
Refund reading
There may be a moderate overpayment signal worth reviewing
The gap is noticeable enough that a tax-code issue, job change, emergency tax period, or payroll adjustment may be worth reviewing.
Important note
Refund outcomes can depend on tax code history, job changes, emergency tax, cumulative PAYE, benefits, and HMRC records. This page is a first-check estimate only.
Decode the tax code
Best when the possible overpayment may be linked to the PAYE code applied.
Check the payslip pattern
Useful when you want to inspect year-to-date PAYE and NI instead of relying on one refund estimate.
Open salary calculator
Return to the broader salary route for full take-home context.
2026/27
Current UK tax year
HMRC / GOV.UK
Reference sources
Estimate
Free estimate using 2026/27 UK tax-year reference rules with HMRC/GOV.UK guidance points.
Next