This question is asked by many people each year, especially if their circumstances have changed. Perhaps they have found themselves starting a side hustle or have been in receipt of dividend income for the first time.

As income tax is self assessed, the onus is on the individual taxpayer to determine whether or not they have an obligation to file their own self assessment income tax return.

If in doubt, you could of course choose to err on the side of caution and register for self assessment but this would result in additional administration – most obviously, registering with HMRC and filing an annual tax return – which many would prefer to avoid.