Tax Refund Estimator 2026/27
Estimate if you're owed a tax refund from HMRC. Millions of UK taxpayers overpay through PAYE each year — check if you're due money back.
From your P60 or payslips
From your P60
What is a P800 tax calculation?
A P800 is HMRC's end-of-year tax calculation. It shows if you've paid too much or too little tax through PAYE. You'll receive a P800 by post or online if there's a difference between what you paid and what you owe.
Why might I have overpaid tax?
Common reasons include: wrong tax code, starting a new job mid-year, receiving taxable benefits, multiple jobs with split personal allowance, or emergency tax codes. Around 1 in 3 PAYE taxpayers overpay.
How do I claim a tax refund?
If HMRC sends you a P800 showing you're owed a refund, you can claim it online via your Personal Tax Account. The refund is usually paid within 5 working days. If you don't claim online, HMRC will send a cheque within 60 days.
How far back can I claim a tax refund?
You can claim a tax refund for the last 4 tax years. For example, in 2026/27 you can claim back to 2022/23. After 4 years, unclaimed refunds are lost.
Do I need to do anything if I've underpaid?
If you've underpaid, HMRC will usually collect it by adjusting your tax code for the next year. For underpayments over £3,000, you may need to pay directly through Self Assessment.
Wrong Tax Code
Check your code is 1257L
Emergency Tax
New job without P45
Multiple Jobs
Split personal allowance
Job Changes
Mid-year income changes