Written and reviewed by James Whitfield · Updated for 2026/27 · Editorial standards · Methodology
How employees get overpaid tax back from HMRC: the automatic payroll and P800 routes, claiming after you stop work, job expenses and Marriage Allowance, the 4-year time limit, and why you never need a refund company.
If you pay tax through PAYE, most overpaid tax comes back automatically: through your payslip once HMRC corrects your tax code, or by a P800 after the tax year ends1. You claim yourself, free, through your HMRC personal tax account: a P800 refund claimed online arrives within 5 working days2. Use form P50 if you stopped work mid-year, and claim job expenses or Marriage Allowance for up to 4 previous tax years (back to 2022/23 until 5 April 2027).
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Typical default outputs for quick context.
If you are employed all year and your tax code is right, PAYE takes the right tax and there is nothing to claim. Overpayments come from a wrong code, a job change, or something payroll cannot see, such as job expenses you pay yourself.
Within the tax year, a corrected code fixes most problems. Your code is cumulative, so when HMRC sends your employer the right code, the next payslip refunds the tax overpaid since 6 April. After the year ends on 5 April, HMRC compares what you earned with what was taken. If you paid too much, you get a P800 or a Simple Assessment letter1.
Sam earns £3,000 a month in April and May 2026, then leaves. Payroll applies the cumulative 1257L code, so the tax for those two months is £781.00. Sam starts a new job in October at the same pay but has lost the P45, ticks statement B on the starter checklist, and the new employer uses the emergency code 1257L M1. That gives one month's allowance (£1,047.50) each payday and takes £390.50 a month.
| Pay | Income tax | |
|---|---|---|
| April to May, first job (cumulative 1257L) | £6,000.00 | £781.00 |
| October to March, new job (1257L M1) | £18,000.00 | £2,343.00 |
| Total paid | £24,000.00 | £3,124.00 |
| Tax actually due on £24,000 | £2,286.00 | |
| Overpaid: refund due | £838.00 |
M1 gives one month's personal allowance per payday and ignores the allowance Sam did not use from June to September. Once HMRC switches the code to cumulative, the next payslip repays the difference; if it is never switched, the P800 after 5 April does.
| Situation | How to claim | Typical value |
|---|---|---|
| Emergency tax after a job change | Update your code; otherwise P800 | Hundreds of pounds |
| Stopped work part-way through the year | Form P50 (online or post) | Unused personal allowance × 20% |
| Uniform washing (flat-rate expense) | Personal tax account, up to 4 years back | £12 a year at the standard £60 rate, basic-rate taxpayer |
| Professional fees on HMRC's approved list | Personal tax account, up to 4 years back | 20% or 40% of the fee |
| Marriage Allowance not claimed | GOV.UK Marriage Allowance claim, backdated 4 years | Up to £252 a year |
| Higher-rate relief on personal pension payments | Personal tax account or Self Assessment | An extra 20% of the gross contribution |
Values are for basic-rate taxpayers unless stated. Expenses your employer reimburses cannot also be claimed.
The general limit for reclaiming overpaid income tax is 4 years from the end of the tax year it relates to. As at October 2026 you can claim for 2022/23, 2023/24, 2024/25 and 2025/26, as well as the current year once it ends. Claims for 2022/23 must reach HMRC by 5 April 2027.
A P800 does not have a claim deadline printed in the same way, but claim it as soon as it arrives. If you do nothing and the letter says a cheque is coming, HMRC posts it within 14 days of the date on the letter2.
There is no need. Every route on this page is free and run by HMRC. Refund companies submit the same forms and keep a percentage of what comes back, and if you sign an authority they can have the refund paid to them first.
If you are unsure whether your code is right, check it yourself first: the code, the pay and tax to date on your latest payslip, and the income HMRC holds for each job in your personal tax account. Most errors show up in one of those three places.
Current tax-year thresholds used across this guide and calculator.
Sign in to your HMRC personal tax account or the HMRC app. Check your tax code and the income HMRC holds, claim any P800 refund online, and claim job expenses or Marriage Allowance there too. If you stopped work during the year, use form P50. It is free.
A P800 refund claimed online is paid within 5 working days. If your P800 says a cheque is coming, it arrives within 14 days of the letter. A cheque you ask for takes about 6 weeks. A corrected tax code refunds in-year overpayments on your next payslip.
Usually 4 years from the end of the tax year. In October 2026 you can claim for 2022/23 to 2025/26, and the 2022/23 deadline is 5 April 2027.
Yes. Once your employer gets your correct cumulative tax code, the next payslip refunds the difference. If the code is not corrected during the year, HMRC's P800 calculation after 5 April refunds it.
No. Claiming through HMRC is free. Refund companies use the same HMRC forms and keep a share of the refund.
No. HMRC does not send refund links by text or email. Sign in to your personal tax account directly to check.
The rates, thresholds and rules on this page are drawn from the official UK government sources below, using the confirmed 2026/27 figures. Each link opens the relevant HMRC or GOV.UK page in a new tab.
Verified against published UK government guidance for 2026/27.