Who Needs to File a Self Assessment Tax Return? (2026/27)
Not everyone in the UK needs to file a Self Assessment tax return, but HMRC applies a specific set of criteria to decide who does. Getting this wrong in either direction causes problems: filing when you didn’t need to wastes time, while missing a required filing triggers automatic penalties even if you don’t owe any tax. This guide from Filing Accounts UK sets out exactly who needs to file for the 2026/27 tax year, using only verified facts from official HMRC and GOV.UK guidance.
At Filing Accounts, we prepare and file Self Assessment returns for UK individuals and businesses. Not sure if you need to file? Check directly using HMRC’s official online tool.
Who Needs to File a Self Assessment Return
Self-Employed Individuals and Sole Traders
If your gross self-employment income (before expenses) exceeds the £1,000 trading allowance in the tax year, you must register for Self Assessment and file a return. This applies whether you work full-time for yourself or earn side income alongside employment, including gig economy work. It applies even if the business made a loss.
Landlords with Rental Income
If your gross rental income exceeds the £1,000 property income allowance, you must declare it via Self Assessment. This includes UK and foreign property, residential and commercial lets, furnished holiday lettings, and short-term lets such as Airbnb. Even where little or no tax is ultimately due after expenses, landlords may still need to report the income.
Company Directors
Being a director does not automatically require a Self Assessment return. Most directors file because they receive untaxed income — typically dividends above the £500 dividend allowance — which must be reported and taxed through Self Assessment. If all your income is taxed through PAYE with no dividends or other untaxed income, you may not need to file.
Partners in a Business Partnership
Business partners must file a return each year to report their share of partnership income, even if that share is modest.
High Earners
Individuals earning £150,000 or more entirely through PAYE are required to file — a threshold that replaced the older £100,000 rule. This exemption for lower earners only applies where income is fully taxed at source with no other filing triggers, such as untaxed dividends or capital gains.
Anyone with Capital Gains Above the Exempt Amount
If you’ve sold or disposed of assets such as property (excluding your main home), shares, or business assets, and your gain exceeds the £3,000 annual exempt amount for 2026/27, you must report and pay Capital Gains Tax via Self Assessment.
Individuals Affected by the High Income Child Benefit Charge (HICBC)
The HICBC applies where an individual in the household earns between £60,000 and £80,000 and Child Benefit is claimed. Since summer 2025, some employees have been able to pay this charge through their PAYE tax code instead of Self Assessment — but many people still need to file, depending on how the charge is being collected in their case.
Anyone with Other Untaxed Income
This includes foreign income, dividends and investment income, savings interest exceeding your personal savings allowance, commission or casual earnings, and chargeable event gains on life insurance policies. It’s easy to overlook smaller amounts, but HMRC looks at your total income across all categories.
Anyone HMRC Sends a Notice to File
If HMRC issues you a formal notice to file, you must submit a return by the deadline — even if you don’t otherwise meet the criteria above and even if you owe no tax — unless HMRC agrees in writing to withdraw the notice.
Important: Making Tax Digital Now Replaces Self Assessment for Some
Since 6 April 2026, self-employed individuals and landlords with combined qualifying income from self-employment and/or property exceeding £50,000 (based on their 2024/25 income) no longer file a traditional Self Assessment return for that income. Instead, they must follow the new Making Tax Digital for Income Tax rules — keeping digital records and submitting quarterly updates, unless exempt. This threshold drops to £30,000 from April 2027, and £20,000 from April 2028, bringing more taxpayers into MTD over time.
Income tax payment dates are unaffected by this change and remain the same as under traditional Self Assessment. Personal tax not covered by MTD — such as dividends from your own company — is still reported through the normal Self Assessment route, so many directors will find themselves running both systems in parallel.
Key Self Assessment Deadlines
For the 2025/26 tax year (6 April 2025 to 5 April 2026), the deadlines are:
| Deadline | Date |
|---|---|
| Register for Self Assessment (if new) | 5 October 2026 |
| Paper tax return | 31 October 2026 |
| Online tax return and payment | 31 January 2027 |
Missing the online filing deadline triggers an automatic £100 penalty even if you owe no tax at all, with further escalating penalties the longer a return remains outstanding.
Watch Out for Payments on Account
If your Self Assessment tax bill is more than £1,000, and less than 80% of your tax has already been collected through PAYE, HMRC usually requires Payments on Account — advance payments toward your next year’s tax bill, each typically 50% of your previous year’s bill. This is one of the most common reasons people are caught out by a larger-than-expected first tax bill.
How to Register
The registration route depends on your situation:
- Form CWF1 — if you’re self-employed
- Form SA1 — if you’re not self-employed (for example, a director or landlord)
- Form SA401 — if you’re registering as a partner in a partnership
Once registered, HMRC posts your Unique Taxpayer Reference (UTR), usually within 2–3 weeks. You can’t file without it, which is why leaving registration until close to the deadline is risky.
Common Mistakes to Avoid
Assuming HMRC Will Tell You If You Need to File
HMRC does not always contact people proactively. If you meet the criteria, it’s your responsibility to register and file — not HMRC’s to remind you.
Overlooking Small Amounts of Untaxed Income
Bank interest, small dividends, commission, and casual earnings are commonly missed, but they all count toward your filing obligations.
Not Realising MTD Now Applies Instead of Self Assessment
If your qualifying self-employment or property income exceeded £50,000 in 2024/25, check whether you should now be following Making Tax Digital rules rather than filing a traditional return.
Leaving Registration Too Late
Your UTR can take 2–3 weeks to arrive by post — register well before the filing deadline, not right before it.
Frequently Asked Questions
Do I need to file if I have no tax to pay?
Possibly yes. HMRC’s Self Assessment criteria don’t provide an automatic exception just because no tax happens to be due — if you meet the criteria, or HMRC has issued you a notice to file, you generally still need to submit a return.
Do company directors always need to file a Self Assessment return?
No. It depends on whether you receive untaxed income such as dividends. If all your income is taxed through PAYE, you may not need to file.
What’s the trading allowance threshold for the self-employed?
£1,000 gross income before expenses. Below this, you generally don’t need to register or file for that income.
What happens if I file late?
An automatic £100 penalty applies from the first day you’re late, even if no tax is owed, with further penalties the longer it remains unfiled.
Does Making Tax Digital replace Self Assessment entirely?
Only for qualifying self-employment and property income above the relevant threshold. Other income, such as dividends, is often still reported via traditional Self Assessment alongside MTD.
Not Sure If You Need to File? Talk to Filing Accounts UK
Self Assessment criteria can be surprisingly easy to misjudge, especially with Making Tax Digital now changing the picture for many self-employed people and landlords. At Filing Accounts, we help UK individuals and businesses confirm exactly what they need to file, register correctly, and submit on time.
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