Written by the TaxTune Editorial Team · Reviewed by our qualified accountants · Updated for 2026
The quick answer You generally need to file a Self Assessment return if you were self employed and earned over £1,000, received rental income, had significant untaxed income, are a company director with untaxed income, earn over £150,000, or need to pay the High Income Child Benefit Charge.

You usually need to file if any of these apply

  1. You were self employed and your trading income was more than £1,000.
  2. You received rental income from property, above the £1,000 property allowance.
  3. You had untaxed income, for example savings interest or dividends above your allowances.
  4. You or your partner claim Child Benefit and one of you earns above the High Income Child Benefit Charge threshold.
  5. You earn over £150,000, or have capital gains to report above the annual exempt amount.
  6. HMRC has sent you a notice to file, in which case you must, even if the tax due is zero.

What to do next

If any of these apply, register for Self Assessment by 5 October following the end of the tax year, then file online by 31 January. If you are genuinely unsure, it is worth a quick check rather than a guess, because filing late or not at all brings automatic penalties.

Still not sure?

The rules have grey areas, especially with side income and dividends. TaxTune will tell you in minutes whether you need to file, register you if so, and handle the return.

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Frequently asked questions

Do I need to file a tax return?

Usually yes if you were self employed earning over £1,000, received rental income, had significant untaxed income, earn over £150,000, or need to pay the High Income Child Benefit Charge. HMRC may also send a notice to file.

Do I file if I am employed and taxed through PAYE?

Often not, if all your tax is collected through PAYE. But you may still need to if you have untaxed income on the side, high income, or the Child Benefit charge applies.

Do landlords need to file?

Yes, if rental income is above the £1,000 property allowance. You report the rent and allowable costs on a Self Assessment return.

What if HMRC sent me a notice to file?

You must file the return even if you owe no tax. Ignoring a notice to file brings the automatic £100 late filing penalty.

What happens if I should have filed but did not?

Register and file as soon as possible. HMRC charges penalties and interest, but coming forward voluntarily usually reduces them compared with being found out.