What does overpaid tax mean?
Overpaid tax means more Income Tax has been paid or deducted than was ultimately due for the relevant tax period.
Under PAYE, employers and pension providers normally deduct Income Tax using information contained in your tax code. If the information available at the time does not accurately reflect your circumstances, the amount deducted during the year may not match your final liability.
If you have paid too much Income Tax, you may be entitled to a repayment. The correct way to obtain it depends on how the overpayment arose and whether HMRC has already reconciled your tax position.
Common reasons people overpay Income Tax
Incorrect tax code
A tax code based on incomplete or outdated information can result in too much tax being deducted.
Changing jobs
Starting a new job without complete PAYE information can sometimes result in temporary or emergency deductions.
Stopping work
If you stop working part-way through a tax year, tax may have been deducted on the assumption that your income would continue for the rest of the year.
More than one PAYE income
Multiple jobs or pensions can make the allocation of tax codes and allowances more complicated.
Unclaimed tax relief
Qualifying employment expenses can sometimes reduce the amount of income on which tax should ultimately be charged.
PAYE reconciliation
HMRC may identify after the tax year that your deductions did not match your final Income Tax position.
How can you check whether you've paid too much tax?
Start by comparing the tax information you have for the relevant year. Useful documents can include your payslips, P45, P60 and any tax calculation or coding information from HMRC.
You should check whether the income and tax deducted shown on those records look complete and whether your tax code reflected your actual circumstances.
HMRC also provides an online tool to help people identify the correct route for claiming an Income Tax refund where too much tax has been paid.
What is a P800 tax refund?
HMRC can carry out an end-of-year reconciliation of PAYE records. If the calculation shows that you paid too much Income Tax, HMRC may issue a P800 tax calculation explaining the overpayment.
A P800 is a tax calculation, not automatically a mistake
It compares information HMRC holds about your income, tax deducted and relevant allowances or adjustments.
If the calculation says you are due a repayment, follow the instructions HMRC provides with the calculation.
Before accepting the figure, it is sensible to check that the income and tax details shown on the P800 match your own records.
You can also read our P800 Tax Refund Guide .
What if you have stopped working?
A refund may arise during the current tax year if you stop working and have paid Income Tax earlier in the year.
HMRC has a specific P50 process for some people who have stopped working and have not started another job, depending on their circumstances.
You should use HMRC's eligibility guidance rather than assuming a P50 is appropriate for every person who leaves a job.
What if you complete a Self Assessment tax return?
If you are within Self Assessment, your final tax calculation can result in a repayment where you have paid more tax than is due.
HMRC provides a separate process for claiming repayments shown on a Self Assessment account.
This is particularly relevant for self-employed people, CIS subcontractors and others who complete tax returns.
How do you claim overpaid tax back from HMRC?
There is not one single refund process for every Income Tax overpayment. HMRC directs taxpayers to different routes depending on the reason for the refund.
P800 tax calculation
If HMRC has issued a P800 showing a repayment, follow the repayment instructions associated with that calculation.
Stopped working
HMRC's P50 process may apply to eligible people who have stopped work during the current tax year.
Self Assessment
If your Self Assessment account shows that HMRC owes you money, use the Self Assessment repayment process.
Other Income Tax overpayments
HMRC's refund checker can direct you to the appropriate process for your particular type of overpayment.
What information should you have before checking a refund?
The exact information required depends on the type of claim, but it is useful to gather your tax records before reviewing an overpayment.
- Your National Insurance number.
- Payslips for the relevant period.
- Your P45 if you left a job.
- Your P60 for completed tax years where available.
- HMRC tax code notices.
- Any P800 tax calculation received.
- Details of other jobs, pensions or taxable income.
- Evidence supporting any qualifying employment expenses being claimed.
A refund should be based on your actual tax position. An amount deducted through PAYE is not automatically repayable simply because it feels high — income, tax codes, allowances and other relevant circumstances all need to be considered.
Reviewed & Updated
11 August 2026
Income Tax & PAYE refunds
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HM Revenue & Customs / GOV.UK
Tax repayment routes depend on the reason for the overpayment and your individual circumstances. HMRC processes and guidance can change, so current official guidance should always be checked before submitting a claim.
Overpaid Tax FAQs
How do I know if I've overpaid tax?
Check your income, tax deducted, tax code and HMRC records for the relevant period. HMRC may also identify an overpayment through PAYE reconciliation and issue a P800.
Will HMRC automatically refund overpaid tax?
It depends on the circumstances. HMRC may identify some PAYE overpayments through reconciliation, but other overpayments require you to make a claim through the appropriate HMRC process.
Can changing jobs cause me to overpay tax?
It can. PAYE deductions can be affected if your new employer does not initially have complete information or if an emergency or other temporary tax code is used.
What should I do if my P800 says HMRC owes me money?
First check that the income and tax figures shown are correct. If they are, follow the refund instructions HMRC provides with the P800 calculation.
Can I claim tax back if I stopped working?
Potentially. HMRC has a P50 process for some people who stop working during the tax year, but eligibility depends on what happens after you leave the job and your wider circumstances.
Can I get a refund if my tax code was wrong?
Potentially. If an incorrect tax code resulted in more Income Tax being deducted than was ultimately due, the difference may be repayable after your tax position is corrected and calculated.
HMRC & GOV.UK Sources
This guide is reviewed against current HMRC guidance on Income Tax overpayments and repayment routes.
Think you've paid too much Income Tax?
Go Tax Refunds can help review your PAYE records, tax code, employment history and relevant tax relief to establish whether an Income Tax repayment may be due.
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