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Do You Need to Complete a Self Assessment Tax Return?

Wondering whether you need to complete a self-assessment tax return? More than 10 million people need to fill one in so if you run your own business, either as a sole trader or in a partnership, completing a tax return is absolutely necessary.

In this guide, you’ll find out who needs to file a tax return and why they need to do so. I’ll also explain exactly what HMRC needs to know and answer some of the other questions you might have on this topic.

1. Who Needs to Complete a Self Assessment Tax Return?

Self-assessment is a process created by HMRC. It allows anyone who receives untaxed income to declare it to the government and pay any tax due. To do this, you use a tax return form (or SA100).

For people in the UK who are employed by someone, their employer will take responsibility for working out their income tax and National Insurance. They do this by deducting both of these and paying it to HMRC on their behalf. They get a payslip and don’t really ever have to deal with HMRC, unless there are changes to their tax codes. Others however, get paid money which is known as untaxed income and it is their responsibility to tell HMRC about it, work out how much tax you owe and pay any tax over after receiving the money. The way they do this is by registering for self-assessment and file a tax return.

Individuals who typically need to complete a tax return include individuals who are:

  • Self-employed or a sole traders
  • Landlords
  • Earned a salary of £100k+
  • Wanting to claim certain income tax reliefs or record a tax loss to use in the future
  • Received interest that was untaxed or not taxed at source. For example, National Savings and Investment account (in general, interest paid by banks or building societies is paid after deducting tax. However, some bank interest may still need to appear on a tax return)
  • Receiving dividends;
  • Earning a gross salary of £50,000, have claimed child benefit and need to pay the high-income child benefit charge;
  • Have savings or investment income of £10,000 or more;
  • Have a capital gain to report such as from selling a second property;
  • Completed one in the previous tax year and HMRC has assumed another should filed this tax year.

There are some types of income that are tax-free such as:

If you are not registered to complete a self-assessment tax return, then you may not need to tell HMRC about this income. However, if you register for self-assessment, then you may need to include some of these types of income on your tax return. This is applicable even though you have no tax to pay. You’ll need to check what you need to do depending on the type of income you’ve received when you fill in your tax return.

2. Will HMRC Tell Me to Fill In a Tax Return?

No, It’s up to you to decide whether you should register for self-assessment and file a tax return. That’s because it is impossible for HMRC to know everyone’s financial affairs. Therefore, they place the trust in us to declare any untaxed income that we receive (and to work out whether we should be telling them or not). That doesn’t mean you can skip filing a return. The tax-man has ways and means of finding out if you should be filing a tax return when you haven’t done so.

3. How To Let HMRC Know You Need to Complete a Tax Return

If you already fill in a tax return for another reason; for example, because you are a landlord or have dividend income, then you don’t need to apply again. If you register for self assessment again, HMRC will set you up on their system for a second time and expect two tax returns from you! Instead, you should complete a CWF1 Form online.

If you are registering because you have become self-employed, then read this guide to registering as self-employed or if you are registering a partnership, then read this guide to to find out how to set up a partnership because the forms are slightly different.

3.1 How to Register to Complete a Self-Assessment Tax Return

4. How To Cancel a Self Assessment Tax Return

If you have received a request from HMRC to complete a tax return but feel you don’t meet the criteria to need to do so, call them on 0300 200 3310. You can discuss your situation and ask if they can withdraw the return.