What is a Self Assessment Tax Return and Who Needs to File One

If you live or work in the UK, you may have heard about Self Assessment tax returns. But what exactly are they, and how do you know if you need to complete one? Here’s a clear guide to help you understand the essentials.

What is a Self Assessment Tax Return?

Self Assessment is HMRC’s system for collecting income tax. For most people in the UK, tax is deducted automatically through PAYE (Pay As You Earn) from wages, pensions, or savings.

But if you have income that isn’t taxed at source, you need to report it to HMRC yourself through a Self Assessment tax return. This ensures you pay the correct amount of tax (or claim back any tax you’ve overpaid).

Who Needs to File a Self Assessment?

You’ll need to file if, in the last tax year (6 April to 5 April), any of the following apply:

• You’re self-employed as a sole trader and earned more than £1,000.

• You’re a partner in a business partnership.

• You’re a company director receiving dividends or benefits not taxed through PAYE.

• You’re a landlord earning rental income.

• You’ve had capital gains from selling property, shares, crypto, or other assets.

• You earn more than £150,000 a year.

• You receive untaxed income such as tips, commission, side hustles, or freelance work.

• You have foreign income from working abroad, overseas investments, or rental property.

• You’re a trustee or executor handling an estate.

• You or your partner claim Child Benefit and one of you earns over £60,000.

Even if you’re employed under PAYE, you may still need to file if you have additional income sources.

Who Doesn’t Need to File?

You don’t need to complete a Self Assessment if:

• All your income is taxed through PAYE (and earn under £150,000).

• You only receive state pension (and it doesn’t exceed your personal allowance).

• Your extra income is within the £1,000 trading allowance or £1,000 property allowance.

Key Deadlines You Need to Know

• Register for Self Assessment: by 5 October following the end of the tax year.

• Paper tax returns: by 31 October.

• Online tax returns & payment: by 31 January.

Missing these deadlines could mean penalties, even if you don’t owe tax.

Final Thoughts

If you have any income that isn’t automatically taxed, there’s a good chance you need to complete a Self Assessment. It can feel overwhelming at first — but with the right guidance, it’s straightforward.

Need help? We take care of the entire process, from calculating your tax bill to submitting your return on time — so you can avoid penalties and focus on what matters most.