UK self-assessment for freelancers: the plain English guide (no accountant needed)

UK self-assessment is genuinely not that hard. But HMRC has done a terrible job of explaining it. Here's the plain English version for freelancers. What self-assessment actually is It's just a tax return. You tell HMRC: What you earned (from all sources) What your allowable business expenses were HMRC calculates what you owe That's it. Once a year. Deadline: 31 January. Who has to do it If you're self-employed (sole trader or freelance) and earned more than £1,000 from self-employment in a tax year, you must register and file. You also need it if: You earn over £100,000 total You have rental income over £2,500 You have untaxed income (dividends, savings interest above your allowance) The timeline April 6: New tax year starts July 5: Deadline to register as self-employed if you started working for yourself in the previous year October 31: Deadline for paper returns (nobody uses this) January 31: Online return deadline AND payment deadline Here's what catches people out: you pay two thin