It’s not unusual for people to be unclear about whether they must complete a Self Assessment tax return. Each year, thousands of people across the UK are unsure if they must file, especially if they’ve never done it before.
Self Assessment lets you report untaxed income like self-employment, rent, or investments to HMRC. It’s also used to claim tax reliefs or report capital gains.
In this guide, we’ll explain exactly who needs to file a tax return, what income triggers it, how to register, and what happens if you don’t. Whether you’re employed, self-employed, a landlord, or just earning a little on the side, this post will help you stay compliant and avoid penalties.
What Does a Self Assessment Tax Return Involve?
Through Self Assessment, you declare any income to HMRC where tax hasn’t been taken off at source.
UK employees typically pay tax automatically through the government’s PAYE (Pay As You Earn) scheme.But if you receive other income — like from freelancing, renting property, or earning dividends — you’re responsible for reporting it yourself.
Here’s a quick breakdown:
Self assessment is the annual process where you report your income and expenses to HMRC, helping you determine how much tax you owe or if you’re due a refund. By the yearly deadline of 31 January, most people send in their returns online.
You’ll need to register first, get a Unique Taxpayer Reference (UTR), and then complete the return using HMRC’s online portal or accounting software.
What Is Self Assessment?
It’s how you report income that HMRC doesn’t already know about. It’s up to you to calculate and settle any tax liabilities.
Who Needs to File a Self Assessment?
Anyone with non-PAYE income or a request from HMRC must complete a Self Assessment return. This applies to many people—from sole traders and landlords to those earning interest or dividends above the tax-free allowances.
Here’s a breakdown of the most common categories:
People Who Are Self-Employed or Sole Traders
If you run your own business — even as a side hustle — you need to file a self assessment.
You must submit a tax return if:
you earned over £1,000 from self-employment during the tax year, want to claim business expenses or tax relief, or if you’re a partner in a business partnership.
This applies to a wide range of professionals, including freelancers, consultants, tradespeople such as plumbers or electricians, and creative workers like designers, writers, and photographers.
Even if you made a loss or didn’t earn much, HMRC still expects a return if you registered as self-employed.
People With Rental Income
Landlords who earn income from letting property must file a tax return.
You need to submit:
A self assessment tax return if you earn more than £1,000 per year in rental income, rent out a room through Airbnb or other short-term platforms, or own a Buy-to-Let property.
Both residential and commercial landlords are affected — even if the property is jointly owned.
You can deduct allowable expenses (like maintenance or letting agent fees) through your return.
People With Untaxed Savings, Dividends, or Investments
If you earn income from:
Dividends over £500, savings interest beyond your Personal Savings Allowance, or receive income from bonds or trusts, you may need to report it through self assessment—particularly if your total untaxed income exceeds £2,500.
High Earners Earning Over £100,000
If your annual income exceeds £100,000, you’re required to file a self assessment return.
Even if you’re employed and taxed through PAYE, the system may not accurately account for factors like personal allowance reductions, student loan repayments, or additional rate tax—making self assessment necessary in some cases.
High earners often underpay tax through PAYE alone — so HMRC requires a return to reconcile the difference.
Directors or Partners in a Business
If you’re a company director or business partner with dividends or other income not taxed at source.
…you’re likely required to submit a self assessment, even if your salary is paid through PAYE.
Exception: Directors with no income beyond PAYE and no additional tax obligations may not need to file — but check with an accountant or HMRC.
People With Foreign Income or Crypto Gains
You’ll need to:
complete a self assessment tax return if you earned income from abroad—such as overseas pensions, rental income, or a foreign salary—made gains from selling crypto assets, or are a UK resident but non-domiciled and have brought foreign income into the UK.
Cryptocurrency gains count as capital gains, and exceeding the annual exemption threshold requires reporting via self assessment.
Higher-earning parents who get Child Benefit
Claiming Child Benefit while earning over £50,000 means you or your partner will need to file a tax return to account for the High Income Child Benefit Charge.
Who needs to complete a self assessment tax return?
You’ll generally need to file one if you’re self-employed and earn over £1,000, rent out property, have untaxed income such as dividends or interest, or if your annual income exceeds £100,000. Company directors, business partners, those with foreign income or capital gains, and anyone claiming Child Benefit while earning over £50,000 may also be required to submit a self assessment tax return.
Should I complete a Self Assessment if I’m employed?
For most people paying tax via PAYE, completing a Self Assessment tax return isn’t required. However, there are exceptions—often more common than expected. If all your income comes from your employer and is taxed correctly under PAYE, HMRC generally won’t require you to file.
But you will need to file if any of the following apply:
You Have Additional Income
If you earn additional income alongside your main job—such as through freelance or consulting work, a side hustle like selling on Etsy or tutoring, offering services online, or renting out a room or property—you may need to report it to HMRC, especially if it exceeds the tax-free allowance.
Even if your main job is taxed under PAYE, additional income of over £1,000 a year must be reported via self assessment.
You Earn Over £100,000
PAYE systems may not handle all tax obligations accurately at high income levels.
This can lead to:
Earning over £100,000 can lead to a reduced personal allowance, underpaid tax through your salary, or inaccuracies in student loan deductions—all of which may require you to report your income directly to HMRC.
That’s why HMRC automatically requires a return for earners over £100,000, even if they have no other income.
You Receive Benefits or Expense Payments
If you receive:
Company benefits, unreimbursed expenses, and taxable redundancy payments may need to be reported separately to HMRC.
You Claim Tax Relief on Work Expenses
For example, if:
You spend money on job-related equipment or travel and want to claim professional subscriptions (e.g., union or body membership fees)
…you might be advised to file a return to claim back relief, especially if the amount is substantial or recurring.
Employed People Who May Need to File
You might still need to file a self assessment tax return if you earn other income, exceed £100,000, or claim tax reliefs.
Self Assessment taxable income
Who needs to complete a self assessment tax return? You must file if you receive income that HMRC doesn’t automatically tax, especially when it exceeds specific thresholds.
Below are common types of income that often require reporting:
Side Hustle or Freelance Income: Who needs to complete a self assessment tax return?
You may need to file if you sell products online through platforms like eBay, Etsy, or Shopify, provide freelance services such as writing, design, or tutoring, or earn extra income from part-time work like delivery driving or dog walking.
Annual income above £1,000 means you must register as self-employed and report it through a tax return.
This falls under the Trading Allowance — income under £1,000 generally doesn’t need reporting, unless HMRC instructs you.
Even if it’s a hobby, once it’s making money, it’s taxable.
Rental Income (Including Airbnb or Room Letting)
You must file a tax return if:
your property income exceeds £1,000 in a tax year, you rent out a room in your home (including under the Rent a Room Scheme), or you host guests through Airbnb or similar platforms.
You can:
claim expenses such as repairs, letting agent fees, and insurance, and choose to use the £1,000 property allowance or deduct actual costs—whichever benefits you more.
Joint owners must each report their share of rental income.
Capital Gains From Shares, Crypto, or Property
You must report capital gains if:
you sell shares, crypto assets, second homes, or valuable items like art, especially if your total gains exceed the £3,000 annual exemption or if you dispose of property that isn’t your main residence.
Cryptocurrency is treated like property for tax purposes, so if you’ve sold or swapped tokens, that may trigger a tax return.
You must report gains even if your total income is otherwise low.
Dividends or interest exceeding the tax-free allowance: Who needs to complete a self assessment tax return?
While the UK provides a £500 tax-free dividend allowance and a Personal Savings Allowance of up to £1,000 depending on your tax band, you’ll still need to complete a self assessment if your untaxed dividends or interest go beyond these limits.
If you exceed these, you’ll need to:
If your dividend income exceeds the tax-free allowance, you must report it through self assessment and pay the correct dividend tax rates of 8.75%, 33.75%, or 39.35%, depending on your income level.
Foreign Income or Overseas Pensions
You must complete a return if you:
earn rental income from abroad, receive overseas pensions, work abroad while still a UK tax resident, or own assets generating income outside the UK.
Foreign tax paid doesn’t remove your obligation to tell HMRC; however, you may use Foreign Tax Credit Relief to stop double taxation.
Common Sources of Income That Need Self Assessment
You must file if your self-employed earnings exceed £1,000, you receive rental income over £1,000, have capital gains above £3,000, earn dividends or interest beyond the tax-free allowances, or if you have income from abroad or cryptocurrency.
Checking Whether You Need to Submit a Tax Return
HMRC has an online tool to help if you’re unsure about completing a Self Assessment tax return. You answer a few questions about your income sources, and it tells you whether you need to register and file.
But there are also some practical signs to watch for, especially if your finances are more complex.
Access HMRC’s checker to see if you must file a tax return.
Look for this tool on GOV.UK using the search term:
“Check if you need to send a Self Assessment tax return”
The tool takes you through a short quiz, asking about Employment status, Income types and amounts, Child Benefit, Capital gains,Tax reliefs or expenses
At the end, it will confirm if you need to file — and if so, tell you when to register.
HMRC Self Assessment Check Tool
You’ve Received a Notice to File from HMRC
Sometimes, HMRC sends a “Notice to File a Tax Return” — even if you think you don’t need to.
If you get this, you must either:
File the return, or formally request to withdraw it (with a valid reason)
Ignoring it can result in penalties, even if no tax is owed.
You’re on the Borderline (Just Under a Threshold)
If you’re wondering who needs to complete a self assessment tax return, anyone with income from side hustles, property, or dividends near the thresholds should keep detailed records, check for applicable allowances like the £1,000 trading or property allowance, and consider filing voluntarily to avoid potential issues with HMRC later.
You’ve Stopped Earning or Changed Circumstances
If you’ve filed before but no longer meet the criteria, inform HMRC that you no longer need to submit a return. Not completing it without notice could lead to immediate penalties.
Example: You sold your rental property last year and now have only PAYE income.
Not Certain If You Must File?
Use HMRC’s free tool, check your income sources, and always respond to a notice to file — even if your situation changed.
Self Assessment Registration: When and How to Do It
If you are not sure who needs to complete a self assessment tax return, before submitting, first-time filers must complete registration with HMRC. Registration is a separate step with its own deadline. When you register, HMRC assigns you a Unique Taxpayer Reference (UTR) to include in your annual returns.
Self Assessment: Key Dates for Registration
Make sure to register by 5 October in the year after you earned the income.
Example:
You must register by 5 October 2025 for any untaxed income earned between 6 April 2024 and 5 April 2025.
Failing to register on time can lead to:
- Penalties
- A delay in getting your UTR (which you need to file)
- Missed filing deadlines later
How to Register (Step-by-Step)
- Visit GOV.UK to register for Self Assessment and get your UTR.
- Choose the correct route
Based on your situation:
- Self-employed or sole trader
- Not self-employed (e.g. landlord, investor, high earner)
- Partner in a business partnership
- Set up a Government Gateway account
Verification requires an email, phone number, and valid ID.
- Submit your details to HMRC
Include your National Insurance number and income type. - Await your UTR number
Within about 10 working days, HMRC will post your 10-digit UTR to your home.
Registered Before? No Need to Re-register
Having filed before means you already have a UTR. You don’t need to register again; just access your account through Government Gateway.
Tip: Make sure to keep your UTR and login details safe for annual filing.
Self Assessment Sign-Up
To file, register by 5 October after the tax year you earned untaxed income and get your UTR.
What Happens If You Don’t File?
Missing the self assessment deadline — or failing to register at all — can lead to automatic penalties, interest, and possible enforcement by HMRC.
No tax owed? You can still face a late filing penalty
Key Deadlines to Remember
- Register for Self Assessment: by 5 October
- Submit Online Tax Return: by 31 January
- Pay Any Tax Owed: by 31 January
If you file after 31 January or pay late, HMRC starts charging penalties immediately.
Late Filing Penalties
| Delay | Penalty |
| 1 day late | £100 fixed fine (even if no tax owed) |
| 3 months late | £10 per day (up to £900) |
| 6 months late | Extra £300 or 5% of tax owed |
| 12 months late | Another £300 or up to 100% of tax |
These penalties stack — and apply even if you file voluntarily but miss the deadline.
Charges for Late Tax Payments
Late tax payments may result in the following:
Who needs to complete a self assessment tax return? If you meet the criteria and fail to pay on time, be aware of penalties: a 5% surcharge after 30 days, another 5% after six months, and a further 5% after 12 months, plus daily interest currently around 7.75%.
Even if you’re struggling financially, HMRC expects you to get in touch early — they may allow a Time to Pay arrangement.
What If HMRC Contacts You?
If you receive a Notice to File but don’t think you need to:
Don’t ignore a notice to file. You must either submit your return or ask HMRC to cancel it. If approved, your penalties may be cancelled.
How to Appeal a Penalty
If you’re unsure who needs to complete a self assessment tax return but miss a deadline due to a reasonable excuse like serious illness, bereavement, HMRC online problems, or lost documents, you can appeal online through your Government Gateway or submit a written explanation to HMRC.
Submit any appeal within 30 days of receiving the penalty notice.
Penalties at a Glance
Who needs to complete a self assessment tax return? If you’re required to file, missing the deadline triggers a £100 fine the very next day, with further penalties at three, six, and twelve months, plus interest and 5% surcharges on unpaid tax. Always reach out to HMRC if you’re unsure or having difficulties.
Common Questions AboutSelf Assessment (People Also Ask)
Do students need to complete a self assessment?
Usually not — unless they earn untaxed income.
If a student earns more than £1,000 a year from freelancing, tutoring, reselling online, or rental income, they may need to file a tax return. Income from part-time PAYE jobs typically doesn’t require self assessment.
What if I made a loss as a sole trader?
Filing a return is still necessary and could be advantageous.
Losses from self-employment don’t remove the need to file a tax return. The good news: you can carry forward the loss to offset future profits or claim a loss relief.
Can I stop sending tax returns if my situation changes?
Yes — but you must formally tell HMRC.
If you’re unsure who needs to complete a self assessment tax return but have stopped earning reportable income, contact HMRC to close your record. You must keep filing until they confirm..
Do pensioners need to file a self assessment?
Losses don’t exempt you from the obligation to file a tax return.
For pensioners with:
Who needs to complete a self assessment tax return? You’ll need to file if your private pension income goes beyond tax-free allowances, you receive interest or dividends above permitted limits, or you have rental or other side income to report.
…making it necessary for them to submit a tax return.
State Pension alone does not usually require self assessment unless it exceeds the personal allowance.
Can I file jointly with my spouse?
No — the UK tax system is individual-based.
Each person must register, file, and pay tax on their own income. However, you may still benefit from marriage Allowanceand joint ownership deductions for property income (each partner reports their share)
Students and pensioners may need to file based on income. Losses must be reported to reduce future tax. Notify HMRC if you no longer need to file. Returns are filed individually in the UK.
Conclusion: How to Meet Filing Requirements
You may need to submit a Self Assessment tax return if you:
If uncertain about filing, self-employed earners over £1,000 must complete a Self Assessment tax return; receive rental income from properties or Airbnb; get dividends, interest, or savings above tax-free limits; have capital gains from selling assets; earn foreign income or overseas pensions; are company directors, business partners, or high earners over £100,000; claim Child Benefit with income over £50,000; received a Notice to File from HMRC; or want to claim tax reliefs or report losses.
You likely don’t need to file if:
If you’re fully employed and taxed through PAYE with no other income, receive only a State Pension below the personal allowance, or have side or investment income under £1,000 (within the trading or property allowance), you typically don’t need to file a tax return.
What to Do Next
Step 1: Use HMRC’s Online Check ToolCheck if you need to file
Step 2: Register by 5 October (if you’re new to self assessment)
Step 3: File your return by 31 January (and pay any tax owed)
Step 4: Get support if needed — don’t guess when it comes to tax
