Check your HMRC tax refund: P800 letters explained

What is a P800, and who gets one?

A P800 is HMRC's tax calculation letter. It explains whether an employee or pensioner paid too much or too little Income Tax by the end of the tax year on 5 April. It tells you how to claim a refund or pay what you owe.

HMRC sends letters between June and March of the following tax year. If you are registered for Self Assessment, your bill adjusts automatically: you do not get a P800 or Simple Assessment letter.

A calculation can follow a wrong tax code, incorrect income information, or a job change where both employers paid you in the same month. Starting to receive a pension at work, Employment and Support Allowance or Jobseeker's Allowance can also lead to a calculation.

A Simple Assessment letter is different. It can arrive where tax cannot be collected automatically, you owe more than £3,000, or you must pay tax on State Pension. For other correspondence, see our HMRC letters guide.

This guide reflects the position during 2026/27. Rules can change, so check the current GOV.UK guidance on tax calculations. RR Accountants is not HMRC and cannot decide eligibility on your behalf.

How to check if you are due an HMRC tax refund

Go directly to your personal tax account or use the HMRC app. Check the income and tax recorded for the year concerned.

The last year's Income Tax service shows tax paid from 6 April 2025 to 5 April 2026. HMRC calculates everyone's Income Tax between June and November. You cannot use this service if you paid any part of last year's Income Tax through Self Assessment. You must sign in and may need photo ID to prove your identity. The HMRC app can also show this information.

For 2026/27, use Check your Income Tax for the current year. You can check or update your tax code and employment details through your account or the app. If HMRC corrects your code and you are due a refund, your employer gives it through your pay once it receives the new code.

Our 1257L guide and emergency tax-code guide explain the codes themselves. For sign-in problems, use the HMRC online services helpdesk.

If your P800 says you are due a refund

Follow the instructions on your letter. The claim route determines the timing.

• Your letter says you can claim online: use the online bank transfer service or request a cheque online. You need the P800 reference number and your National Insurance number. GOV.UK says money is sent within 5 working days for an online claim, or within 6 weeks if you ask HMRC for a cheque.
• Your letter says HMRC will send a cheque: there is no need to contact HMRC to claim. It arrives by post within 14 days of the letter date. Refunds covering more than one year come in a single cheque for the total.

You can also claim through your personal tax account or the HMRC app if you have a UK bank account, or contact HMRC. Start with GOV.UK's P800 guidance. The last year's Income Tax service can also be used to claim or pay if your P800 says you can do this online.

No P800 yet: how to check a tax rebate

For tax paid from 6 April 2025 to 5 April 2026, GOV.UK says you should get a P800 by 30 November 2026 if HMRC works out you paid too much. That date is specific to 2025/26.

For tax paid from 6 April 2022 to 5 April 2025, GOV.UK says that no P800 probably means you paid the right amount. If you think you overpaid, check each year in your personal tax account and send an update for each year, or contact HMRC. If a refund is due, GOV.UK says you usually receive it within 3 weeks. Its current tool says tax paid before 6 April 2022 cannot be reclaimed.

Use Check how to claim a tax refund to find the route for your circumstances. It covers employment pay, job expenses, Self Assessment returns or bills, redundancy payments and other income. The tool itself cannot submit a claim.

Self Assessment users do not receive a P800: their bill adjusts automatically. For tax paid on or after 6 April 2026 in your current job, a corrected code can bring the refund through your pay once your employer receives it.

If your P800 says you owe tax

HMRC usually collects an underpayment by changing your tax code. Collection is in equal instalments over 12 months from the start of the following tax year. This happens automatically where all three conditions apply:

• You pay Income Tax through an employer or pension provider.
• You earn enough above your Personal Allowance to cover the underpayment.
• You owe less than £3,000.

Otherwise, HMRC writes to explain how to pay. Our 2026/27 Personal Allowance guide explains the allowance.

Illustration: a £450 underpayment divided over 12 months is £37.50 of extra tax a month for a monthly-paid employee. HMRC collects it through the tax code; the effect on pay depends on the code. This is an illustration, not a calculation of your bill.

You can pay before the following tax year starts. Routes include online bank approval, debit or corporate credit card, bank transfer, or cheque. You cannot use a personal credit card. For bank transfers, the 17-character reference combines your National Insurance number, P800 and the first year of the tax year. Follow the exact instructions in GOV.UK's P800 payment guide.

What if the calculation is wrong?

Contact HMRC and explain which amounts are incorrect and what they should be. If HMRC agrees, it sends a new calculation. If it disagrees, it contacts you to explain why.

Spotting tax refund scams

HMRC does not send details of tax refunds by email. Go to GOV.UK or sign in to your own account directly instead of following a refund link in a message. Use GOV.UK to report suspicious emails, texts and calls.