Good to know
Clear guidance, in plain terms.
General information to help you understand this area — not personal advice. Rules, thresholds and deadlines can change, so check the latest HMRC guidance or ask us about your circumstances.
Key deadlines
For a tax year ending 5 April, you must usually register for Self Assessment by 5 October, file a paper return by 31 October, and file online and pay any tax due by 31 January. Payments on account may also fall due on 31 January and 31 July.
Who needs to file
Filing is typically required for the self-employed, landlords, company directors, higher earners and anyone with significant untaxed income such as dividends, crypto or capital gains. If in doubt, it’s best checked early rather than close to the deadline.
Penalties for lateness
Missing the filing deadline triggers an automatic £100 penalty even if no tax is owed, with further penalties and interest the longer a return or payment stays outstanding.
Landlords & property income
Rental profits are reported on the property pages of your return. Finance costs such as mortgage interest are relieved as a basic-rate tax reducer rather than a deduction, and the furnished holiday lettings rules were abolished from 6 April 2025, so holiday lets are now taxed like other rental income.
Content creators & influencers
Income from platforms, brand deals, affiliate links and subscriptions is generally taxable, and gifted products or trips received in return for promotion can count as income too. Overseas platforms may withhold foreign tax, which often needs reporting and can affect what you owe here.
Making Tax Digital for Income Tax
MTD for Income Tax began on 6 April 2026 for sole traders and landlords with qualifying income over £50,000, extending to those over £30,000 from April 2027 and £20,000 from April 2028. Those in scope keep digital records and send quarterly updates plus a final declaration using compatible software.
Allowances worth knowing
The trading allowance and the property allowance each let you receive up to £1,000 of that income before it needs reporting, and rent-a-room relief can apply to letting a furnished room in your own home. Whether they help depends on your wider position.
Higher earners
Once adjusted net income passes £100,000 the personal allowance tapers away, creating an effective marginal rate of around 60% on income between £100,000 and £125,140. Pension contributions and Gift Aid are common ways of managing this.