If you earn income outside your regular salary, there’s a good chance you may need to complete a Self Assessment tax return.
With more people earning money through freelance work, property income, side businesses, investments, and online platforms, Self Assessment now applies to far more than just the self-employed.
HMRC won’t always contact you to tell you that you need to file. If you meet the criteria, it’s your responsibility to register, submit your tax return, and pay any tax owed on time.
Missing deadlines can lead to penalties and interest charges, even if you didn’t realise you needed to complete a return.
In this guide, we explain who needs to file a Self Assessment tax return for the 2026/27 tax year, the most common situations that apply, and the deadlines you need to know.
Who Needs to File a Tax Return in 2026/27?
You may need to complete a Self Assessment tax return if you receive income that is not fully taxed through PAYE.
Below are some of the most common situations where a tax return may be required for the 2026/27 tax year.
Self-Employed People and Sole Traders
If you’re self-employed or running a side business, you’ll usually need to file a Self Assessment tax return if your total income before expenses is more than £1,000 during the tax year.
This is known as the trading allowance.
Self Assessment can apply whether you work full-time for yourself or earn additional income alongside employment.
Examples of self-employment income include:
- freelance work,
- consulting,
- online selling,
- content creation,
- delivery driving,
- tutoring,
- social media or influencer income,
- selling services online.
Many people are surprised to learn that online selling can sometimes count as taxable income. Selling unwanted personal items occasionally is usually not taxable, but regularly buying or making items to sell for profit may need to be declared to HMRC.
This is a common area of confusion for people selling through platforms such as Etsy, Ebay, Vinted, Depop, or Facebook Marketplace.
Landlords and Property Income
You’ll usually need to file a tax return if you earn income from property that exceeds the £1,000 property allowance.
This can include:
- residential rental income,
- holiday lets,
- overseas property income,
- income from land or commercial property.
If you rent out a room in your home, the Rent a Room scheme may allow you to earn up to £7,500 tax-free, depending on your circumstances.
Even if little or no tax is due after expenses, landlords may still need to report rental income to HMRC.
Company Directors
Being a company director does not automatically mean you need to complete a Self Assessment tax return.
However, many directors still need to file because they receive:
- dividend income,
- untaxed income,
- benefits or expenses,
- income from multiple sources.
If all of your income is taxed through PAYE and you have no additional reporting requirements, you may not need to submit a tax return.
High Earners and Child Benefit
The previous rule requiring people earning over £100,000 to automatically file a tax return has now been removed.
However, some higher earners may still need to file, particularly if they are affected by the High Income Child Benefit Charge (HICBC).
From Summer 2025, some employees have been able to pay the HICBC through PAYE instead of Self Assessment. However, many people still need to submit a tax return depending on their circumstances and how the charge is collected.
If you or your partner claim Child Benefit and your adjusted net income exceeds the HICBC threshold, it’s important to check whether you need to file.
Investment, Dividend, and Savings Income
You may need to complete a tax return if you receive untaxed income from investments or savings.
This can include:
- dividend income,
- savings interest above your allowance,
- income from investments,
- cryptoasset income or gains,
- disposals of shares or other investments.
Although some investment income is covered by allowances, higher levels of income may still need to be reported to HMRC.
Income earned through ISAs is generally tax-free and does not need to be declared.
Capital Gains Tax
You may need to file a tax return if you sell or dispose of assets and make a taxable gain.
This can include:
- shares and investments,
- second properties,
- cryptoassets,
- business assets.
In some cases, you may need to report capital gains even if no Income Tax is due.
Foreign Income
Foreign income may also need to be declared through Self Assessment.
This can include:
- overseas pensions,
- rental income from property abroad,
- foreign investments,
- overseas employment income.
This is particularly important for remote workers, digital nomads, or people with income from multiple countries.
Other Reasons You May Need to File
Other situations where a Self Assessment tax return may be required include:
- receiving income from a trust,
- pension tax charges,
- CIS subcontractor income,
- bankruptcy cases,
- ministers of religion,
- being specifically asked by HMRC to file a return.
If HMRC issues a notice to file a tax return, you must normally submit one even if you believe no tax is due.
Situations Where You May No Longer Need to File
Recent changes to HMRC rules mean some people who previously completed a Self Assessment tax return may no longer need to.
The £100,000 Income Rule Has Changed
In the past, people earning more than £100,000 were usually required to submit a tax return automatically.
This is no longer the case.
If all of your income is taxed correctly through PAYE and you have no other reporting requirements, you may not need to complete a Self Assessment purely because your income exceeds £100,000.
However, other factors such as dividend income, property income, or capital gains may still mean a return is required.
Child Benefit Changes
Changes to the High Income Child Benefit Charge (HICBC) mean some employees can now pay the charge through PAYE instead of completing a Self Assessment tax return.
This will not apply to everyone, and many households affected by the charge may still need to file depending on their circumstances.
If you or your partner receive Child Benefit and your income exceeds the HICBC threshold, it’s important to check how the charge is being collected.
HMRC May Cancel Your Filing Requirement
If your circumstances have changed, HMRC may tell you that you no longer need to complete a tax return.
However, you should not stop filing without checking first.
If HMRC has issued a notice to file a tax return, you usually still need to submit one unless HMRC officially withdraws the requirement.
Not Sure if You Need to File?
If you’re unsure whether you need to complete a Self Assessment tax return, it’s important to check rather than assume.
Missing a required tax return can lead to penalties and interest charges, even if no tax is owed.
You can use HMRC’s online Self Assessment checker, or speak to an accountant who can review your circumstances and confirm whether you need to register or file.
Self Assessment Deadlines for 2026/27
If you need to complete a Self Assessment tax return, it’s important to keep track of the key deadlines throughout the tax year.
Missing deadlines can lead to automatic penalties and interest charges from HMRC.
Key Self Assessment Deadlines
| Deadline | Date |
| Register for Self Assessment | 5 October 2027 |
| Paper tax return deadline | 31 October 2027 |
| Online tax return deadline | 31 January 2028 |
| Tax payment deadline | 31 January 2028 |
If any deadline falls on a weekend or bank holiday, HMRC must usually receive your return or payment by the deadline itself.
Payments on Account
Many taxpayers are surprised to receive a larger than expected tax bill because of Payments on Account.
Payments on Account are advance payments towards your next tax bill. They are usually required if your Self Assessment tax bill is more than £1,000 and less than 80% of your tax has already been collected through PAYE.
Payments are normally due in two instalments:
| Payment | Deadline |
| First payment on account | 31 January |
| Second payment on account | 31 July |
Each payment is usually based on 50% of your previous year’s tax bill.
For example, if your tax bill for 2026/27 is £4,000, HMRC may ask for:
- £4,000 for the 2026/27 tax year,
- plus £2,000 as the first payment on account for 2027/28.
This is one of the most common reasons people receive a higher than expected Self Assessment bill for the first time.
What Happens if You Don’t File?
If you’re required to submit a Self Assessment tax return and miss the deadline, HMRC can charge penalties and interest even if you do not owe any tax.
The longer a return or payment remains outstanding, the more expensive it can become.
Late Filing Penalties
HMRC applies automatic penalties for late Self Assessment tax returns.
£100 Automatic Penalty
If your tax return is submitted after the deadline, you’ll usually receive an automatic £100 late filing penalty, even if no tax is owed.
Daily Penalties After 3 Months
If your return is more than 3 months late, HMRC can charge additional daily penalties of £10 per day for up to 90 days.
This means penalties can increase by up to £900 on top of the initial £100 fine.
6-Month Penalties
If your return is still outstanding after 6 months, HMRC may charge a further penalty of:
- 5% of the tax due, or
- £300, whichever is greater.
12-Month Penalties
After 12 months, another penalty may apply of:
- 5% of the tax due, or
- £300, whichever is greater.
In serious cases where HMRC believes information has been deliberately withheld, penalties can be significantly higher.
Interest on Late Tax Payments
HMRC also charges interest on unpaid tax from the date the payment becomes overdue until it is paid in full.
Interest rates can change throughout the year and are linked to the Bank of England base rate. As rates have increased in recent years, late payment interest charges can add up quickly on unpaid tax bills.
How to Register for Self Assessment
If you’ve never completed a Self Assessment tax return before, you’ll need to register with HMRC before you can file online.
You can register for Self Assessment through the GOV.UK website.
Once registered, HMRC will issue you with:
- a Unique Taxpayer Reference (UTR),
- and access to your Government Gateway account.
Your UTR is a 10-digit number used to identify you for Self Assessment and other tax matters.
It’s important to register well before the deadline, as it can take time for HMRC to process your registration and send your UTR details.
What You Need Before Filing
Before completing your Self Assessment tax return, make sure you have the relevant records and documents available.
Employment Income
You may need:
- P60 forms,
- P45 forms if you changed jobs,
- P11D forms for benefits or expenses,
- details of employment benefits and expenses.
Self-Employment Records
If you’re self-employed, useful records include:
- invoices and sales records,
- business bank statements,
- receipts for allowable expenses,
- mileage or travel records where relevant.
Property Income
Landlords should gather:
- rental income records,
- letting agent statements,
- mortgage interest information,
- records of property expenses and repairs.
Investments and Savings
You may need:
- dividend statements,
- savings interest statements,
- investment income summaries,
- details of share disposals.
Pension Information
This can include:
- private pension contributions,
- workplace pension contributions,
- pension income statements,
- records of tax relief claimed.
Cryptoasset Records
If you’ve bought, sold, exchanged, or earned cryptocurrency, you may need:
- transaction histories,
- wallet records,
- details of gains, losses, or income received.
Cryptoasset activity can sometimes create Income Tax or Capital Gains Tax reporting obligations.
Benefits and Other Income
You may also need information relating to:
- taxable benefits,
- trusts,
- foreign income,
- Child Benefit charges,
- other untaxed income.
Common Self Assessment Mistakes
Small mistakes on a tax return can lead to penalties, HMRC enquiries, or paying more tax than necessary.
Forgetting Side Income
Income from freelance work, online selling, side businesses, or casual work can still be taxable even if it’s not your main source of income.
Many people forget to include smaller income streams alongside their employment income.
Missing Dividend or Investment Income
Dividend income, savings interest, and investment income are commonly overlooked, particularly where multiple accounts or platforms are involved.
Even if some income falls within allowances, it may still need to be reported.
Confusing Turnover With Profit
Self-employed individuals sometimes mistake total sales income for taxable profit.
Tax is usually based on profit after allowable business expenses, not total turnover.
Poor Expense Records
Failing to keep clear records of expenses can make it difficult to claim legitimate tax deductions and support figures reported to HMRC.
Keeping organised records throughout the year can make filing much easier.
Forgetting Payments on Account
Many taxpayers are caught out by Payments on Account, especially during their first year of Self Assessment.
This can result in a much larger tax bill than expected in January.
Assuming HMRC Will Remind You
HMRC does not always contact people to tell them they need to file a tax return.
If you meet the criteria for Self Assessment, it’s your responsibility to register and submit your return on time.
Missing Crypto Gains
Cryptoassets are still frequently overlooked on Self Assessment tax returns.
Selling, exchanging, or using cryptocurrency can sometimes create Capital Gains Tax or Income Tax liabilities, even where no cash has been withdrawn to a bank account.
Need Help With Self Assessment?
Self Assessment can quickly become complicated, especially if you have income from multiple sources, property, dividends, or investments.
At Ryans, we help individuals, landlords, company directors, and self-employed businesses manage their tax returns accurately and on time.
Our team can help with:
- registering for Self Assessment,
- preparing and submitting tax returns,
- rental property income,
- dividend and director tax returns,
- Capital Gains Tax reporting,
- tax planning and allowances,
- reducing the risk of penalties and HMRC issues.
Whether you’re filing for the first time or need support with a more complex tax situation, we can help make the process straightforward and stress-free.
To discuss your Self Assessment requirements, contact Ryans today.
Self Assessment FAQs for 2026/27
Do I need to file a tax return if I’m employed?
Not always. If all of your income is taxed correctly through PAYE, you may not need to complete a Self Assessment tax return.
However, additional income from property, dividends, side businesses, investments, or Child Benefit charges may still mean you need to file.
What happens if I made less than £1,000?
If your total self-employment or side income is less than £1,000 before expenses during the tax year, you may not need to register for Self Assessment because of the trading allowance.
This depends on your overall circumstances and whether other reporting requirements apply.
Do company directors need to file a tax return?
Not automatically.
Some company directors still need to complete Self Assessment because they receive dividends or other untaxed income. However, directors whose income is fully taxed through PAYE may not need to file.
Do I need to declare Vinted or Ebay sales?
Selling unwanted personal belongings occasionally is usually not taxable.
However, if you regularly buy, make, or sell items with the intention of making a profit (of over £1,000 per tax year), HMRC may treat this as trading income that needs to be declared.
Can HMRC fine me if I didn’t know I needed to file?
Yes. HMRC can still charge penalties for missing Self Assessment deadlines even if you were unaware you needed to file.
If you think you may need to complete a return, it’s important to check as early as possible.
Can an accountant file my tax return for me?
Yes. An accountant can prepare and submit your Self Assessment tax return on your behalf, help ensure figures are accurate, and identify tax reliefs or allowances you may be entitled to claim.
When do I stop filing tax returns?
You can usually stop filing Self Assessment tax returns if you no longer meet HMRC’s filing requirements.
However, you should not stop submitting returns unless HMRC confirms that your Self Assessment record has been closed or your notice to file has been withdrawn.