Do I Need to Do a Tax Return? (UK Self Assessment Checklist)

“Do I actually need to do a tax return?” is one of the most common — and most important — tax questions, because getting it wrong (not filing when you should) leads to penalties. Here’s a clear checklist.

You probably need to file if…

You generally need to complete a Self Assessment tax return if any of these applied in the tax year (6 April to 5 April):

You were self-employed (a sole trader) earning more than £1,000
You rented out property and made rental income
You’re a company director with untaxed income to report
You earned over £150,000
You had significant dividend income (above the £500 allowance) or savings/investment income
You had Capital Gains Tax to pay (sold property, shares or a business at a gain)
You received other untaxed income HMRC doesn’t already know about
HMRC sent you a notice to file

If one or more applies, you should be registered for Self Assessment.

You probably don’t need to file if…

You generally don’t need to file if:

All your income is from employment and taxed through PAYE, and
You have no significant other income, gains or reasons above

In that case, your tax is handled automatically and there’s nothing to submit.

The grey areas that catch people out

A few situations trip people up:

A job and a side hustle: if the side income is over £1,000, you file — even though you’re employed. See how to register as a sole trader.
Becoming a landlord: rental income means a return — see landlord tax explained.
Dividends above £500: investors and directors often need to file.
Capital gains: selling a second property or shares at a gain can require reporting (property within 60 days).
Earning over £100,000: the personal allowance starts to taper, and a return is often needed.

Should have filed but didn’t?

If you realise you should have registered and filed but haven’t, the best move is to put it right promptly — register, file the outstanding returns, and pay any tax. There are penalties for being late, but coming forward voluntarily is far better than waiting for HMRC to find you.

Not sure? Let’s check

The rules have enough grey areas that plenty of people either file unnecessarily or — more dangerously — fail to file when they should. If you’re unsure, our Self Assessment service confirms whether you need to file, gets you registered if so, and handles the return — so you’re compliant without the guesswork. For the full overview, see Self Assessment explained.

Frequently asked questions

Do I need to do a Self Assessment tax return?

You generally need to file if you were self-employed earning over £1,000, received rental income, are a company director with untaxed income, earned over £150,000, had significant dividend or savings income, had Capital Gains Tax to pay, received untaxed income HMRC doesn't know about, or were told by HMRC to file. If none apply and you're taxed fully through PAYE, you usually don't.

Do I need to do a tax return if I'm employed?

Usually not — if all your income is from employment and taxed through PAYE, your tax is handled automatically. But you may still need to file if you have other untaxed income (a side business, rental income, big dividends), earn over £150,000, or want to claim certain reliefs. Having a job doesn't exempt you if you have other reportable income.

Do I need to do a tax return for a side hustle?

If your gross income from self-employment (including a side hustle) is more than £1,000 in a tax year, yes — you need to register for Self Assessment and file a return, even if you also have a regular job. Below £1,000 you're covered by the trading allowance and usually don't need to.

Do I need to do a tax return for dividends?

If your dividends exceed the £500 dividend allowance and you don't already file, you may need to — either through Self Assessment or, in some cases, by HMRC adjusting your tax code. Company directors and investors with significant dividend income generally file a return. We can confirm your position.

What happens if I should have filed but didn't?

If you should have registered and filed but didn't, you should put it right as soon as possible — register, file the outstanding returns and pay any tax. HMRC charges penalties and interest for late registration and filing, but coming forward voluntarily is far better than waiting for HMRC to catch up, which can mean bigger penalties.

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Reviewed by Provense Accountants

Written and reviewed by our team of qualified accountants (AAT-regulated). This guide is general information, not personal tax advice — book a free consultation for advice on your situation.