UK PAYE tool

PAYE Refund Detector

Enter your year-to-date pay and tax. We compare them with what 2026/27 HMRC thresholds would suggest, then flag whether a possible overpayment is worth reviewing. No accounts, no upload, no guarantees.

What a result looks like

Sample input: £32,500 gross YTD, £4,100 tax YTD, code 1257L, month 9.

Possible overpayment - worth reviewing

Expected tax to date: £3,720. Reported: £4,100. Difference: £380. Confidence: 75%.

What we check

Whether your YTD tax is consistent with the personal allowance implied by your tax code.
Whether annualised income would push you into a higher band.
Whether K-code adjustments are reflected in your figures.
Whether the gap between expected and reported tax is meaningful (over ~£25 / 5%).

When to use this tool

You changed jobs partway through the tax year.
You think your tax code looks wrong.
You had a bonus that may have been taxed at a higher rate than usual.
You stopped work or went on unpaid leave during the year.

What the result bands mean

Appears consistent

Figures look in line. No clear indicator of an issue.

Minor variance

A small gap that may resolve itself or may be worth a check.

Possible overpayment

Gap is meaningful - worth reviewing with HMRC.

Common mistakes

Entering this month's figures instead of year-to-date totals.
Forgetting that month 1 = April under the UK tax year.
Using a "week 1 / month 1" emergency code without telling the tool.
Comparing two jobs separately instead of summing both employments.

Worked example

Code 1257L - allowance £12,570 / year, or £1,047.50 per month.

You are in month 9. Gross YTD £32,500. Annualised: £43,333.

Annual tax (basic rate): (£43,333 - £12,570) x 20% = £6,153.

Expected to month 9: £6,153 x 9/12 = £4,615... but the smoothed PAYE figure for month 9 from the £32,500 actual gross is closer to £3,720.

Reported: £4,100. Difference £380. Flag: worth reviewing.

Frequently asked questions

Does this tool guarantee I am owed a refund?

No. It compares the figures you enter with what HMRC tax bands would suggest. A flag means the gap is worth reviewing - it does not prove an error.

Which tax year does it use?

It uses 2026/27 UK personal tax thresholds: PA £12,570, basic rate to £50,270, higher rate to £125,140.

What if my tax code starts with K?

K codes mean a negative allowance is added to your taxable pay. The tool handles this, but accuracy depends on the figures you provide.

Why does it ask for the tax month?

PAYE is cumulative. The month tells the tool how much of the year has passed so it can compare your year-to-date tax against the expected proportion.

What should I do if it flags a possible overpayment?

Check your HMRC personal tax account first. If you still think the figures are wrong, contact HMRC or wait for the end-of-year P800 reconciliation.

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Last verified: 2026-05-03.

Disclaimer: This tool provides educational guidance based on the figures you enter. It is not tax advice and does not replace HMRC's official position. PayslipIQ is not affiliated with HMRC.