Tax overpayments and underpayments
1. Your tax calculation
If you’re employed or get a pension, HM Revenue and Customs (HMRC) checks whether you’re paying the right amount of tax throughout the year.
They may adjust your tax during the year if your circumstances change, for example if you get a pay rise or a company benefit.
When you might get a P800
You might get a P800 if you:
- finished one job and started a new one in the same month
- started receiving a pension at work
- received Employment and Support Allowance or Jobseeker’s Allowance
You won’t get a P800 if you’re registered for Self Assessment. Your bill will be adjusted automatically if you’ve underpaid or overpaid tax.
P800s are sent out after the tax year ends on 5 April. You’ll normally get yours by the end of October.
Checking your P800
Compare the figures with your records, for example your P60, bank statements or letters from the Department for Work and Pensions. If your state benefit was paid every 4 weeks, work out the total paid in a year by multiplying your regular payment by 13 (not 12).
You may be able to use the HMRC tax checker to work out how much tax you should have paid.