If you’ve not paid the right amount of tax
If you’ve paid too much or too little tax by the end of the tax year (5 April), HM Revenue and Customs (HMRC) will send you either:
- a tax calculation letter (also known as a P800)
- a Simple Assessment letter
This will tell you how to get a refund or pay tax you owe.
This guide is also available in Welsh (Cymraeg).
You’ll only get a letter if:
- you are employed
- you get a pension
If you’re registered for Self Assessment, your bill will be adjusted automatically if you’ve underpaid or overpaid tax. You will not get a tax calculation letter or a Simple Assessment letter.
When letters are sent
The letters are sent out between June and the end of November.
Why you might get a tax calculation letter
You might get a tax calculation letter if you either owe tax or are owed a refund because you:
- were put on the wrong tax code, for example because HMRC had the wrong information about your income
- finished one job, started a new one and were paid by both in the same month
- started receiving a pension at work
- received Employment and Support Allowance or Jobseeker’s Allowance
Why you might get a Simple Assessment letter
You might get a Simple Assessment letter if you:
- owe tax that cannot be automatically taken out of your income
- owe HMRC more than £3,000
- have to pay tax on your State Pension
Find out how to pay your Simple Assessment bill.
You’ll need to pay the tax you owe by a certain deadline.
If you have not been sent a tax calculation letter or a Simple Assessment letter
If you think you have paid too much tax and HMRC have not sent you a tax calculation letter, find out how to claim a refund.
If you think you owe tax and you have not received a letter, contact HMRC.