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Self Assessment Returns

Self Assessment Tax Returns

Whether you’re self-employed, a landlord or have income from multiple sources, our experts can help you file your Self Assessment tax return.

We’ll prepare your return, calculate what you owe and submit it to HMRC accurately and on time. Making Self Assessment simpler, while helping you claim the allowances and expenses you’re entitled to.

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Who needs to file a Self Assessment tax return?

You may need to file a Self Assessment tax return if you:

  • Are self-employed and earn more than £1,000 in gross trading income
  • Are a partner in a business partnership
  • Receive rental income from property or land
  • Receive untaxed income, such as tips or commissions
  • Receive savings interest, dividends or other investment income
  • Receive taxable income from overseas
  • Have Capital Gains Tax to pay
  • Need to pay the High Income Child Benefit Charge
  • Need to report income as an off-payroll worker
  • Need to repay a student or postgraduate loan through Self Assessment

How we can help with your Self Assessment tax return

  • Prepare your return: We review your income, expenses and relevant tax information and prepare your return.
  • Calculate what you owe: We calculate your tax liability and explain what needs to be paid and when.
  • File with HMRC: We submit your Self Assessment tax return and help you meet the relevant deadlines.
  • Answer your tax questions: Get expert support on allowable expenses, additional income, property income and other Self Assessment matters.
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Who can we help with Self Assessment?

We help people with a wide range of income and circumstances manage their Self Assessment.

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Sole traders and self-employed people

Help with business income, expenses and tax returns.

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Freelancers and contractors

Support with income, expenses and Self Assessment filing.

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Landlords

Help report rental income and allowable property expenses.

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Company directors

Support with personal tax returns and additional income.

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People with investment income

Help report dividends, interest and investment income.

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People with overseas income

Assistance with reporting taxable foreign income correctly.

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Partnerships

Help partners report their share of partnership income.

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Individuals with complex tax affairs

Support with multiple income sources and tax matters.

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What information do I need to complete a self assessment?

You’ll need various documents to complete your Self Assessment tax return, such as:

  • Employment income records, such as your P60 or P45
  • Self-employment income and business expenses
  • Bank and savings interest
  • Rental income and property expenses
  • Dividends and investment income
  • Pension contributions
  • Details of any capital gains
  • Overseas income, where applicable
  • Details of other taxable income
  • Information about any tax already paid

Self Assessment tax return deadlines

Deadline What you need to do
5 October Register for Self Assessment if you need to file for the previous tax year
31 October Submit a paper tax return
31 January Submit an online tax return and pay tax owed
31 January Pay the first payment on account, where applicable
31 July Pay the second payment on account, where applicable

Self Assessment and Making Tax Digital for Income Tax


MTD for Income Tax started on 6 April 2026. It initially applies to sole traders and landlords with qualifying income above £50,000

  • The threshold reduces to £30,000 from April 2027
  • It reduces again to £20,000 from April 2028
  • Taxpayers joining MTD still need to submit their tax return for the previous tax year
  • Quarterly updates are submitted using compatible software

HMRC confirms that the £20,000 threshold applies from 6 April 2028, based on qualifying income for 2026/27.

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Penalties for filing your Self Assessment tax return late

If you miss the Self Assessment filing deadline, you may face penalties under the existing regime:

  • Late filing: An initial £100 penalty.
  • More than 3 months late: £10 per day, up to a maximum of £900.
  • More than 6 months late: A further £300 or 5% of the tax due, whichever is greater.
  • More than 12 months late: A further £300 or 5% of the tax due, whichever is greater. Higher penalties can apply in some circumstances.

Different penalty rules apply to taxpayers moving into Making Tax Digital for Income Tax. Need help meeting the deadline? Talk to dns accountants about getting your Self Assessment sorted.

Common Mistakes in Self Assessment Filings

Many taxpayers make errors when submitting their Self Assessment tax return. Here are the most common mistakes:

  • Missing the deadline can lead to HMRC penalties.
  • Not declaring all income can trigger tax checks or investigations.
  • Forgetting to claim allowable expenses increases your tax bill.
  • Entering incorrect income or expense figures.
  • Failing to include relevant savings, investment or property income.
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Frequently Asked Questions

Self Assessment is a system used by HM Revenue and Customs (HMRC) to collect income tax. If you're self-employed, a landlord, or have other income outside of your regular employment, you may need to complete a Self Assessment tax return

Completing a Self Assessment can be complex and time-consuming. A self-employed accountant can help you navigate the intricacies, ensure accuracy, and potentially save you money by identifying tax-saving opportunities.

Yes, we can assist you with late filings and help minimize penalties and interest charges from HMRC.

Yes, if you are a Director of a limited company, you are generally required to complete a Self Assessment tax return. This is especially true if you receive income that is not taxed at source or if you receive dividends from the company.

Yes, you can file a Self Assessment tax return online through the HMRC website. This is often the most convenient method and allows you to instantly submit your tax return, calculate your tax liability, and receive immediate confirmation.

Yes, if you are operating as a sole trader, you are required to complete a Self Assessment tax return. This is how you will report your business income and expenses to HMRC and calculate your sole trader self assessment tax liability.

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