Self Assessment is a system HM Revenue and Customs (HMRC) uses to collect Income Tax.
Tax is usually deducted automatically from wages, pensions and savings. People and businesses with other income must report it in a tax return. If you need to complete a tax return (external link), you need to fill it in after the end of the tax year (5 April), it applies to.
Sending your Tax Return
If you did not send an online return last year, allow extra time (up to 20 working days) as you’ll need to register first. There are different ways to register if you’re:
Filling in your Return
You need to keep records (external link) (for example bank statements or receipts) so you can fill in your tax return correctly. You can get help to fill in your return (external link).
Paying your Bill
HMRC will calculate what you owe (external link) based on what you report.
How much tax you pay will depend on the Income Tax (external link) band you are in. There’s a different rate for Capital Gains Tax (external link) if you need to pay it, for example you sell shares or a second home.