If tax is deducted from your wages each month, you might assume there is nothing else to report to HMRC. That is often the case, but starting a business, letting a property or receiving other income can change your responsibilities. Whether you need to complete a Self Assessment tax return depends on where your income comes from, the amounts involved and your circumstances. There is no single earnings threshold that applies to everyone.
This guide explains who needs to do a tax return, the situations worth checking and what to do if you are unsure.
What Is a Self Assessment Tax Return?
A Self Assessment tax return gives HMRC the information needed to calculate your tax liability. Depending on your circumstances, this may include business earnings, rental income, dividends, taxable gains and any expenses or reliefs you can claim.
Each return relates to one tax year. For example, the 2025/26 tax year covers 6 April 2025 to 5 April 2026.
Submitting a return does not necessarily mean there will be tax to pay. Available allowances may cover your income, but a filing obligation can still apply. HMRC provides guidance on who must send a tax return.
Who Needs to Do a Tax Return?
Self Assessment applies to more than people who run their own businesses. The following are some common reasons you may need to file.
Sole Traders and Self-Employed People
If you work for yourself, you will normally need a return once your total trading income exceeds £1,000 during the tax year. This is measured before deducting expenses.
Activities that count towards this total can include:
- Freelance projects
- Consultancy work
- Selling goods as a business
- Providing paid services alongside your main job
The threshold applies across your trading activities. For example, £800 from freelance work and £500 from a tutoring business would give you £1,300 of trading income.
Expenses that reduce your profit below £1,000 do not remove the filing requirement.
If you are starting out, our Business Start Ups & Growth services can help you choose suitable accounting systems and understand your responsibilities from the beginning.
Partners in a Business Partnership
Individual business partners must complete their own Self Assessment returns, reporting their share of the partnership’s income or losses.
The partnership also submits a separate return. Both the business’s reporting and each partner’s personal tax position therefore need attention; completing one does not replace the other.
Landlords and People Receiving Rental Income
Letting a property can bring you into Self Assessment, including where you became a landlord after inheriting a property or moving out of a former home.
HMRC requires a return where rental income exceeds either:
- £2,500 after allowable expenses
- £10,000 before allowable expenses
Below these amounts, you may still need to contact HMRC to declare the income.
The letting arrangement also matters. Renting a room in your own home may qualify for Rent a Room relief, while other lettings may benefit from the property allowance. Check which rules apply before deciding that no reporting is needed.
People Receiving Dividends or Investment Income
Savings interest and dividends can affect your tax position, although owing tax on them does not always mean you need a return.
Receiving more than £10,000 in dividends requires Self Assessment. If you receive a smaller taxable amount and do not otherwise file, contact HMRC about how to report it. The tax may be collected through your tax code.
Company directors should consider their personal income separately from the company’s finances. Being a director alone does not require a personal return, but dividends or other income may create that obligation.
People With Other Tax Liabilities
You may also need to review your filing requirements if you:
- Receive overseas income that is taxable in the UK
- Sell an asset and have Capital Gains Tax to pay
- Become liable for the High Income Child Benefit Charge
The Child Benefit charge can arise when you or your partner receives Child Benefit and either person’s adjusted net income exceeds £60,000. Broadly, this means total taxable income less certain reliefs, such as qualifying pension contributions.
Eligible people can pay the charge through PAYE. If you need a return for another reason, however, the charge must be included.
Asset sales can have separate reporting deadlines, particularly for property, so check your obligations when the sale takes place.
Do I Need to Do a Self Assessment if I Am Employed?
You will not usually need a return if PAYE correctly deals with all your income and no other filing requirement applies.
From 2024/25 onwards, a high income taxed entirely through PAYE no longer requires a return by itself. Additional income or other tax liabilities can still bring you into Self Assessment.
If HMRC has asked for a return and you believe it is unnecessary, contact them to request withdrawal. Do not simply leave the return unsubmitted.
When Does Your Self Assessment Tax Return Need to Be Submitted?
For the 2025/26 tax year, the main dates are:
- 5 October 2026 – Notify HMRC if you need to register or restart Self Assessment.
- 31 October 2026 – HMRC must receive your paper return.
- 31 January 2027 – Submit your online return and pay the tax due.
Preparing your return early gives you time to check the figures and budget for payment. Your bill may include payments on account, which are advance instalments towards the following year’s tax.
Does Making Tax Digital Affect Your Return?
From April 2026, qualifying sole traders and landlords with qualifying income above £50,000 in 2024/25 must use Making Tax Digital for Income Tax, unless exempt. Joining does not remove the requirement to submit their 2025/26 return.
Our Tax Compliance services can help you understand which reporting requirements apply and prepare your tax return.
Need Help With Your Self Assessment Tax Return?
If your income has changed or you are filing for the first time, MGRW+ can review your circumstances and explain what you need to report. We can also prepare your return and help identify relevant expenses and reliefs.
Get in touch with our accountants to find out whether you need a Self Assessment tax return and get help completing it.