What Is Self Assessment? A Simple Guide
Self Assessment is the system HMRC uses to collect Income Tax from people whose tax is not automatically deducted by an employer. If you are self-employed, a landlord, or have untaxed income, you calculate and report your own tax through Self Assessment.
Who Needs to Do It
- Self-employed people earning over £1,000
- Landlords with rental income
- People with savings or investment income above certain thresholds
- Company directors
- Anyone with foreign income
- Higher earners who need to repay child benefit
How It Works
- Register with HMRC and get a UTR (Unique Taxpayer Reference)
- Keep records of your income and expenses throughout the tax year (6 April to 5 April)
- File your tax return online by 31 January
- Pay any tax owed by 31 January
The Key Date
31 January is the deadline for filing your online return and paying your tax. Miss it, and you face an automatic £100 penalty.
Making It Easy
Software like Accounted tracks your income and expenses automatically throughout the year, calculates your tax, and helps you file your return.
Accounted handles your bookkeeping, tax estimates, and MTD submissions automatically. Start your free trial — no credit card required.
Tax & Compliance Specialists
Our tax specialists have decades of combined experience in UK sole trader and small business taxation, MTD compliance, and HMRC submissions. All content is reviewed against current HMRC guidance before publication and updated quarterly to reflect legislative changes.
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