Self Assessment is a fundamental part of the UK tax system. Yet, many taxpayers remain unsure whether they need to file one, what income is included, and what the consequences of late submission are. Whether you’re newly self-employed, a freelancer, a landlord, or someone with untaxed income, understanding Self Assessment is crucial to staying compliant and avoiding penalties. In this guide, we’ll explain what a Self Assessment tax return is, who needs to file it, what income to report, important deadlines, and how to get help. What Is a Self Assessment Tax Return? A Self Assessment tax return is a method used by HM Revenue and Customs (HMRC) to collect Income Tax from individuals whose earnings are not automatically taxed through the PAYE (Pay As You Earn) system. Self Assessment…