P800 Tax Refund Calculator UK 2026/27
Estimate whether you're due a tax refund from HMRC based on your income, tax paid, and allowable deductions. Compare tax paid vs tax due.
All employment, pension, and other income
From P60 or payslips
Relief at source pension contributions
Work from home, uniforms, tools, subscriptions
Potential Refund
£1,014
Tax Paid
£5,500
Tax Due
£4,486
• Wrong tax code applied by employer
• Started a new job mid-year
• Received a redundancy payment
• Work from home allowance not claimed
• Professional subscriptions unpaid
• Marriage Allowance not applied
• Pension contributions not reflected
How to claim: Log into your Personal Tax Account at gov.uk to check your P800 status and claim refunds online. Refunds typically arrive within 5 working days.
Calculation Methodology
This calculator compares tax paid against tax due based on 2026/27 rates. It accounts for Personal Allowance tapering above £100,000, pension relief, Gift Aid, work expenses, and Marriage Allowance. Actual refunds depend on HMRC records.
Official Sources
Important: Results are estimates based on standard HMRC rules. Your actual tax may differ based on your specific tax code, benefits, or HMRC adjustments. Always verify with your employer or a qualified accountant.
Frequently Asked Questions
What is a P800 tax calculation?
A P800 is a letter from HMRC telling you that you've paid too much or too little tax. HMRC sends these after the end of the tax year when they've checked your records. If you're owed a refund, you can claim online or wait for a cheque. If you owe tax, you'll need to pay it.
Why might I have overpaid tax?
Common reasons include: wrong tax code, changing jobs during the year, receiving multiple pensions, unpaid self-employment expenses (like working from home), not claiming Marriage Allowance, pension contributions not reflected in your code, or stopping work part-way through the year.
How do I claim my P800 tax refund?
If you've received a P800 showing a refund, you can claim online through your Personal Tax Account for faster payment (within 5 days to your bank). Alternatively, wait 45 days and HMRC will send a cheque. You can also call HMRC to request a cheque sooner.
How far back can I claim a tax refund?
You can claim overpaid tax for the last 4 tax years. For example, in 2026/27 you can claim refunds going back to 2022/23. Use form R40 or your Personal Tax Account to claim for previous years. Some claims (like work expenses) can go back further.
What if HMRC says I owe tax?
If your P800 shows you owe less than £3,000, HMRC usually collects it through your tax code over the next year. For larger amounts, you may need to pay directly. You can set up a payment plan if needed. Always check the calculation is correct first.