Who Needs to File a Self Assessment Tax Return?

The Complete List

You must file a Self Assessment tax return if, in the last tax year, you:^[3]

Were self-employed as a sole trader and earned more than £1,000 (before expenses)
Were a partner in a business partnership
Had total income over £150,000
Were a company director (unless for a non-profit with no pay or benefits)
Had untaxed income over £2,500, such as:
- Rental income from property
- Tips and commission
- Income from savings, investments, or dividends
Had savings or investment income of £10,000 or more before tax^[4]
Received dividends over £10,000
Made capital gains above the annual exempt amount (£3,000)
Had foreign income on which you owe UK tax
Received income from a trust or settlement
You or your partner earned over £60,000 and either of you claimed Child Benefit (High Income Child Benefit Charge)
Had income over £100,000 (to calculate Personal Allowance taper)
Owed tax that HMRC couldn’t collect through your tax code

Do I Need to File?

If you’re not sure, HMRC provides a free online tool that asks you a few simple questions and tells you whether you need to submit a return.^[1]

The tool covers the most common scenarios, including employment, self-employment, rental income, and investments.

When in doubt, check. It’s better to file when you don’t need to than to miss a filing you should have made. Late filing attracts automatic penalties. If you do need to file, submitting your return online is the quickest route.

What Happens If You Don’t File

If HMRC expects a return and you don’t file, penalties stack up quickly:^[2]

How Late	Penalty
1 day late	£100 automatic penalty
3 months late	£10 per day, up to 90 days (£900 max)
6 months late	5% of tax due or £300 (whichever is higher)
12 months late	Additional 5% of tax due or £300 (whichever is higher)

These penalties apply even if you don’t owe any tax. On top of penalties, interest is charged on any unpaid tax from the payment deadline.

Voluntary Returns

Even if you’re not required to file, there are good reasons to do so voluntarily:^[2]

Claim a refund — if you’ve overpaid tax (e.g. emergency tax on a pension withdrawal)
Record losses — if your business made a loss, filing records it so you can offset it in future years
Prove your income — some lenders and visa applications accept SA302 tax calculations as proof of earnings

What If HMRC Sends You a Notice to File?

If HMRC sends you a “notice to file” (form SA316), you must submit a return even if you don’t think you need to. You can contact HMRC to explain why you believe you don’t need to file, but until they withdraw the notice, the obligation stands and penalties will apply if you miss the deadline.^[2]

Frequently Asked Questions

Do I need to file a Self Assessment tax return?

You must file if you were self-employed and earned over £1,000, were a company director, had untaxed income over £2,500, had total income over £150,000, or are affected by the High Income Child Benefit Charge, among other reasons.

What happens if I do not file my Self Assessment on time?

HMRC charges a £100 automatic penalty on the first day you are late. After 3 months, an additional £10 per day applies (up to £900). Further penalties of 5% of tax due or £300 follow at 6 and 12 months.

Do I need to file a tax return for rental income?

Yes, if your untaxed rental income exceeds £2,500 per year, or if your total taxable income from all sources exceeds £150,000. Below those thresholds, HMRC may still ask you to file.

What if HMRC sends me a notice to file but I don’t think I need to?

You must submit a return until HMRC formally withdraws the notice. Contact HMRC to explain why you believe you do not need to file, but penalties will apply if you miss the deadline while the notice stands.

Sources

Check if you need to send a Self Assessment tax return — GOV.UK
Self Assessment tax returns — GOV.UK
Self Assessment tax returns: who must send a tax return — GOV.UK
Tax on savings interest — GOV.UK
Register for Self Assessment — GOV.UK