A new online guide from HMRC aims to clarify when individuals must complete a self-assessment tax return, particularly for those earning over £1,000 annually from side hustles. The guidance also highlights that anyone making more than £6,000 from a single item sale may be liable for capital gains tax. The guide, which covers various income sources, including selling personal possessions and providing services, highlights that online platforms will report earnings to HMRC, ensuring compliance with tax regulations.