Do I have to complete a self-assessment tax return?

Although not everybody needs to complete a self-assessment tax return, there are several situations where you could be required to complete one, even when you are an employee and have tax deducted from your wages through Pay As You Earn (PAYE). HM Revenue & Customs (HMRC) can impose penalties if you need to send a tax return but miss the deadline, therefore it is important to be aware of situations where a tax return is needed.

Who needs to file a self-assessment tax return?

You must always send a tax return to HMRC if you: 

• are self-employed, and you earned more than £1,000  
• you are a partner in a business partnership 
• made capital gains above the annual exempt amount and are not eligible for the real-time capital gains tax service
• have untaxed income, such as: 
• money from renting out a property 
• tips and commission 
• income from savings, investments and dividends 
• foreign income 

If your earnings from the above sources fall below certain limits, you may not need to complete a tax return. However, the income may still be subject to tax. A good rule of thumb is that unless the income is tax free, is covered by your tax allowances or tax has been collected through your PAYE code, a tax return is normally required. 

You should always check the position and if you are in doubt, HMRC provides an easy-to-use online tool to confirm if a return is needed.  

Higher earners in receipt of child benefit

If your adjusted net income is more than £60,000 and either you or your partner receive Child Benefit, you will need to pay a tax charge, known as the ‘High Income Child Benefit Charge’ (HICBC).

HMRC will require you to either: 

• complete a tax return to report and pay this charge, or  
• opt to pay it through PAYE 

You can also opt out of receiving Child Benefit payments altogether, which means you would have no HICBC to pay. For 2025/26, the entire Child Benefit you or your partner receive is fully taxed under the charge if you earn £80,000 or more of adjusted net income.  

Landlords with rental income

Most landlords who receive rental income will need to complete a return.

For landlords with undeclared rental income, it is important to address this sooner rather than later. The good news is HMRC have a special Let Property Campaign for landlords who are behind with their tax returns.

By making a voluntary disclosure, you can usually expect a lower penalty than HMRC would normally charge and obtain the best possible terms.

Capital gains tax

Landlords must remember that where Capital Gains Tax (CGT) is due on the disposal of a UK residential property, you must report and pay CGT on the disposal within 60 days from the date of completion of the sale. You can do this: 

• through an online CGT on UK property account or  
• by post if you cannot use the online service.  

If you don’t already have to file a self-assessment tax return, you will not have to file one because of the property sale. However, if you already file a return, you should report the property sale and the CGT paid on it. 

For capital gains on other kinds of assets, you can use the real time capital gains tax service to report and pay the CGT due unless you need to claim foreign tax credit relief or chargeable event gains on life insurance. If you cannot use the real time service, you will need to report the gains on a tax return. 

CGT is a complex tax with many reporting and payment deadlines, as well as potential reliefs that could lead to sizeable savings. It’s therefore important that you seek professional advice.

This above list is not exhaustive, but it will hopefully give you an idea of the sort of things that can trigger the need for a tax return. If you do need to complete a tax return, it’s important that you let HMRC know by 5th October (5th October 2025 for the 2024/25 tax year or 5th October 2026 for the 2025/2026 tax year). 

Need help completing your self-assessment tax return

If you need to complete a tax return for the first time and don’t know where to start, we can help. We offer a great range of tax advice for business owners and landlords and are well-versed in assisting with tax returns. For a free initial consultation, call us today on 01329 623103 or drop us a line using our online enquiry form.

Last updated 9 Jan 2026 | First published 18 Oct 2022

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This article is intended to inform rather than advise and is based on legislation and practice at the time. Taxpayer’s circumstances do vary and if you feel that the information provided is beneficial it is important that you contact us before implementation. If you take, or do not take action as a result of reading this article, before receiving our written endorsement, we will accept no responsibility for any financial loss incurred.

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