What is Self Assessment?
Self Assessment is a system HM Revenue & Customs (HMRC) uses to collect Income Tax. Income Tax is usually deducted automatically from wages, pensions and savings. However, people and businesses with other income must report it in a Self Assessment tax return.
For further guidance see understanding Self Assessment and your tax return.
If you're self-employed you pay Class 2 and Class 4 National Insurance depending on your profits. Most people pay through Self Assessment. Read full guidance on National Insurance.