A P800 tells you that you paid too much or too little Income Tax through PAYE last tax year. Here is how to claim the refund, what happens if you owe tax, and how to challenge the figures.
Claim by bank transfer or request a cheque online with your P800 reference number and National Insurance number. Online claims are paid within 5 working days.
You will get a cheque
No claim needed. The cheque arrives by post within 14 days of the date on the letter, and covers every year you are owed tax for in one payment.
You owe tax
HMRC usually changes your tax code to collect it over 12 months from the next tax year. Owe more than £3,000, or tax that cannot come through your code, and you get a Simple Assessment letter instead.
How to claim a P800 refund
1
Find your P800 reference number
It is on the letter. You also need your National Insurance number.
2
Choose how to be paid
Use HMRC's online service to claim by bank transfer or request a cheque, or claim through your personal tax account or the HMRC app if you have a UK bank account.
3
Wait for the payment
Online claims are paid within 5 working days; a requested cheque takes up to 6 weeks.
4
Check the figures first
If the pay, pension or tax figures look wrong, contact HMRC before claiming and tell them which amounts are incorrect and what they should be.
Why HMRC sends a P800
GOV.UK lists these as common reasons for a tax calculation letter:
Wrong tax code
You were on the wrong tax code, for example because HMRC had the wrong information about your income. Check your current code with the tax code checker.
Two jobs paid in one month
You finished one job, started a new one and were paid by both in the same month.
A workplace pension started
You started receiving a pension from work during the year.
ESA or Jobseeker's Allowance
You received Employment and Support Allowance or Jobseeker's Allowance during the year.
If you have not had a letter, or the letter is a Simple Assessment
Think you overpaid but no P800 has arrived? You can claim a refund yourself rather than wait.
Think you owe tax but have had no letter? GOV.UK says to contact HMRC.
A Simple Assessment letter is a bill: if you got it before 31 October 2026 (for the 2025 to 2026 tax year), pay by 31 January 2027; letters on or after that date are due within 3 months of the letter.
If a Simple Assessment is wrong, you must contact HMRC within 60 days.
Refund texts and emails
A P800 refund is claimed through GOV.UK, your personal tax account or the HMRC app. Treat any text or email with a link offering a tax refund as a scam until you have checked it against HMRC's own guidance.
Frequently asked questions
What is a P800?
A P800 is HMRC's tax calculation letter. HMRC sends it after the tax year ends on 5 April if you paid too much or too little Income Tax through PAYE, and it tells you how to get a refund or pay what you owe.
Who gets a P800?
Only people who are employed or get a pension. If you are registered for Self Assessment, HMRC adjusts your Self Assessment bill automatically instead, and you will not get a P800.
When are P800 letters sent?
Between June and March of the following tax year, so a letter about the year that ended on 5 April can arrive any time from June onwards.
How long does a P800 refund take?
If you claim online, the money is sent within 5 working days. If you ask HMRC to send a cheque, it arrives within 6 weeks. If your letter says HMRC will send a cheque, you do not need to claim: it arrives within 14 days of the date on the letter.
What do I need to claim my P800 refund online?
The reference number from your P800 letter and your National Insurance number. You can also claim through your personal tax account or the HMRC app if you have a UK bank account, or by contacting HMRC.
My P800 says I owe tax. Do I have to pay it now?
Usually not. HMRC collects it by changing your tax code, so the extra tax comes out of your wages or pension in equal instalments for 12 months from the start of the next tax year. That happens automatically if you pay tax through an employer or pension provider, earn enough above your Personal Allowance to cover it, and owe less than £3,000. You can choose to pay before the next tax year starts instead.
What is the difference between a P800 and a Simple Assessment letter?
HMRC sends a Simple Assessment letter instead of a P800 when the tax cannot be taken through your tax code: for example if you owe more than £3,000, or you owe tax on your State Pension. A Simple Assessment is a bill with a payment deadline; it is paid with the 14-character reference starting with 'X' on the letter.
What if I think my P800 is wrong?
Contact HMRC and tell them which amounts you think are incorrect and what they should be. If HMRC agrees, it sends you a new calculation; if it disagrees, it contacts you to explain why.
