Self-assessment is the HMRC system for collecting income tax from individuals whose earnings aren’t taxed automatically, such as the self-employed, landlords and company directors.
Self-assessment vs PAYE
Rather than having your tax deducted through PAYE, you report your income, expenses and other taxable earnings annually through an online or paper tax return. For many people this is fairly straightforward, although according to HMRC a significant number of self-assessment tax payers use an accountant or tax agent.
Using an accountant
Some 40,000 accountancy practices handle tax affairs and many of them deal with self-assessment, such as //chippendaleandclark.com/accountants-near-me/bath/. If you prefer to use a professional service it’s as easy to find accountants Bath, Bolton or Bournemouth as it is in Birmingham, Glasgow and London.
Qualifying for self-assessment
You must usually complete a Self-assessment if you’ve earned over £1,000 as a sole trader, are part of a business partnership, receive rent from property, or earn untaxed income from investments, dividends, or abroad.
Key dates
The tax year runs from 6 April to 5 April, with key deadlines of 5 October to register, and 31 January to file and pay any tax due. From April 2026, HMRC’s Making Tax Digital programme will gradually require online filing and quarterly submissions. Filing early can help you plan payments, reduce stress and receive rebates sooner.
Other important information
You’ll need your Unique Taxpayer Reference, Government Gateway ID, and records of all income and expenses. Missing deadlines can result in escalating penalties, starting with a £100 fine and increasing over time.
