Key takeaways
- A P800 is a tax calculation letter HMRC sends to employees and pensioners who paid too much or too little Income Tax in the last tax year.
- HMRC sends P800s between June and March after the tax year ends on 5 April; letters for 2025/26 are going out now.
- If you claim a P800 refund online, HMRC says the money reaches your bank in 5 working days; a cheque you ask for takes about 6 weeks.
- If your P800 says a cheque is coming, you do not need to do anything; it should arrive within 14 days of the date on the letter.
- Underpaid tax under £3,000 is usually collected through your tax code, in equal instalments over 12 months from 6 April.
- From late September 2026, HMRC began sending P800s and Simple Assessment notices for tax on 2025/26 bank and building society interest.
- HMRC never texts about a tax refund; forward suspicious texts to 60599 and emails to phishing@hmrc.gov.uk.
A P800 is a letter from HMRC showing that you paid too much or too little Income Tax in the last tax year. It goes to employees and pensioners who pay tax through PAYE, not to people who file Self Assessment returns. If you are owed money you can usually claim it online and be paid in 5 working days; if you owe tax, HMRC normally collects it through your tax code.
What is a P800 letter?
A P800 is HMRC’s end of year tax calculation. After the tax year ends on 5 April, HMRC checks the tax taken from your pay and pensions against what you should have paid, and writes to you if the two do not match.
HMRC’s overpayments and underpayments guidance says the letters go out between June and March of the following tax year. For 2025/26, that means June 2026 to March 2027. You may read that most letters are out by the end of November, but GOV.UK does not give that date, so do not assume you have missed out if nothing has arrived by then.
People in Self Assessment do not get a P800. HMRC adjusts their tax bill instead.
Why have I got a P800?
You usually get a P800 because the wrong amount of tax was taken during the year. HMRC lists these common causes:
- you had the wrong tax code, such as an emergency tax code
- you had two jobs or pensions paid in the same month
- you started a workplace pension
- you received Employment and Support Allowance or Jobseeker’s Allowance
Untaxed savings interest is another cause this year. HMRC’s Agent Update issue 147 says that from late September 2026 it began sending P800s or PA302 Simple Assessment notices for tax on bank and building society interest earned between April 2025 and April 2026. Our guide to income tax on savings explains the Personal Savings Allowance.
What if my P800 says I am due a refund?
Your letter says how you will get the money. There are two routes.
| Your P800 says | What to do | When you get paid |
|---|---|---|
| Claim online | Claim by bank transfer online | 5 working days |
| Claim online, cheque chosen | Ask for a cheque | About 6 weeks |
| A cheque will be sent | Nothing | Within 14 days of the letter date |
To claim online, follow these steps:
- Find the reference number on your P800.
- Have your National Insurance number ready.
- Use the GOV.UK claim service, your personal tax account or the HMRC app.
- Enter your UK bank details.
The guidance does not set a deadline for claiming, but claim promptly so the money is not forgotten.
What if my P800 says I owe tax?
HMRC usually collects underpaid tax through your tax code. The owe tax guidance says this happens automatically, in equal instalments over 12 months from 6 April, if all of these apply:
- you pay tax through an employer or pension provider
- you earn enough above your Personal Allowance to cover it
- you owe less than £3,000
You can choose to pay before 6 April online, by bank transfer or by cheque, so your take-home pay is not reduced next year. If HMRC cannot collect through your tax code, or you owe more than £3,000, you may get a Simple Assessment letter instead.
Which applies to you?
Read the top of your letter, then follow the matching line.
- Refund, claim online: claim through GOV.UK or the HMRC app.
- Refund, cheque coming: wait 14 days from the letter date.
- Underpayment under £3,000: check next year’s tax code; nothing else to do.
- Underpayment you want cleared now: pay online before 6 April.
- Simple Assessment letter (PA302): query it within 60 days if it looks wrong.
- Figures look wrong: contact HMRC (see below).
Use our salary take-home calculator to see how a tax code change affects your pay.
What if my P800 is wrong?
Tell HMRC which figures you think are wrong and what they should be. If HMRC agrees, it sends a new calculation; if not, it explains why.
Call HMRC’s Income Tax line on 0300 200 3300, or +44 135 535 9022 from abroad, Monday to Friday, 8am to 6pm. See the Income Tax enquiries page. Check your payslips, P60 and pension statements first.
For joint savings accounts, HMRC splits interest equally between holders, so check that before you call.
Is my P800 a scam?
Treat any refund offer by text or unexpected email as suspect. HMRC says it never texts about a tax rebate, and only emails from addresses ending hmrc.gov.uk. Forward suspicious texts to 60599 and emails to phishing@hmrc.gov.uk. See our guide to HMRC scam calls and texts.
Frequently asked questions
What is a P800 from HMRC?
It is a tax calculation letter showing that you paid too much or too little Income Tax through PAYE in the last tax year.
How long does a P800 refund take?
HMRC says 5 working days if you claim online, 6 weeks if you ask for a cheque, and within 14 days of the letter date if a cheque is sent automatically.
When are P800 letters sent?
HMRC sends them between June and March of the following tax year. For 2025/26, that is June 2026 to March 2027.
Do I have to pay a P800 underpayment straight away?
No. If you owe less than £3,000 and pay tax through PAYE, HMRC usually collects it through your tax code over 12 months from 6 April. You can pay early if you prefer.
Why did I not get a P800 when I think I overpaid?
You can still claim a refund through GOV.UK. If you think you owe tax but got no letter, contact HMRC on 0300 200 3300.
Sources
Rates, thresholds and rules in this guide were checked against HMRC and GOV.UK guidance on 6 November 2026. Tax rules change, so check the current position on GOV.UK or with a qualified adviser before acting. This guide is general information, not personal advice.