Self-assessment tax returns: the complete guide


Self-assessment tax returns: the complete guide


Across the UK, 4.93 million people are self-employed, according to the Office for National Statistics, with each required to file a self-assessment tax return.

According to HMRC, it’s believed that around 5.4 million people haven’t sent in their return, and with the January 31 deadline fast approaching, time is running out. Not filing your tax return will result in a hefty fine, so it’s important to act now to avoid this.

However, this can understandably be a bit intimidating and often seem complicated. That’s why we created this guide to highlight just what exactly a self-assessment tax return is, who needs to file one and how to do so.

What is a self-assessment tax return?

Self-assessment itself is something used by HMRC to work out how much tax you should pay from your income.

For most people, your tax is taken automatically from your wages, pension or savings through a system known as PAYE. However, any other income will need to be reported to HMRC through a self-assessment tax return each year.

You can do this online or by post – although the deadline to send in a paper return is often much earlier, leaving you less time to get organised.

Who needs to file a self-assessment tax return?

Self-assessment tax returns are mainly filed by those who are self-employed. This is a necessity in order to pay income tax and National Insurance on any profits made within the tax year.

You will also need to submit a tax return if you:

  • Claim child benefit and you or your partner earn over £50k a year
  • Are a religious minister
  • Earn £100k or more within the last tax year as an employee or pensioner
  • Need to claim tax relief on your pension contributions (if you’re an additional-rate or higher taxpayer)
  • Are a director or partner of a limited company
  • Earn £2.5k or more in additional untaxed income such as from commission, tips or bonus
  • Owe tax on profits from the sale of an asset, known as capital gains tax
  • Receive taxable income from abroad, or you live abroad and receive a UK income
  • Earn £10k or more through investments or interest on savings

There are some instances where you may have to submit a self-assessment tax return on top of your PAYE tax. For example, if you are receiving payments from a private pension or run a business on top of your regular employment.

For those who run limited companies, you will need to file a company tax return as well as one for your personal income.

How to fill in a self-assessment tax return

If you’re submitting your return online, then this is pretty straightforward – all you have to do is fill out the sections that are relevant to you. You’ll still need to have all your documents including bank statements, your P60 and any loan statements beforehand, however.

This is the quickest way to submit a self-assessment tax return as it will work out your bill automatically for you and you’ll be given a reference number straight away.

If you’re sending a paper return, then you’ll need to go through the form to figure out what sections apply to you. The majority of people will simply need to fill out the SA100 form, but there are multiple additional pages that may be relevant to you, so it’s important to be sure before you post it.

What details do I need to provide?

The main objective when filing your self-assessment tax return is to make sure you’ve covered all the bases and haven’t left anything out that you could be penalised for.

Depending on your situation, you may need to include details regarding:

  • Any benefits you’ve received such as jobseeker’s allowance, incapacity benefit or carer’s allowance
  • The total amount you were entitled to get from state pension payments – which includes any lump sum amount you received
  • Your income – taxed and untaxed – from self-employment, profit from the sale of an asset, shares dividends or interest on savings
  • The gross amount of any payments or lump sums from a private pension
  • Any additional income that’s not connected to dividends or interest
  • Deductions taken for your student loan
  • The total amount of any donations you’ve made to charity (including gift aid donations)
  • If you are claiming Blind Person’s allowance or not

You’ll also need to make sure you have your National Insurance number, unique tax reference (UTR) number and records of any expenses.

Don’t get caught out by the taxman this year. If you’re struggling to pay your tax bill, it’s important to let HMRC know as soon as possible to avoid being fined or charged, which will only cost you more money.

If you’re self-employed and struggling with your finances, contact one of our expert advisors today on 0808 2085 195 or through our online chat service. We’re here to offer you free advice and help you find a solution that works for you.

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