The deadline for submitting a paper copy of the Self-Assessment tax return is fast approaching - midnight on October 31, 2024. In February 2024, it was revealed that a massive 1.1 million people missed the deadline for the previous tax year.

Missing the deadline could result in you having to pay an initial fixed penalty of £100, plus any further additional charges and interest.  

Dan Whittaker, a personal finance expert at VivaMoney.co.uk, shares everything you need to know about the upcoming Self-Assessment tax return deadline, how to check to see whether it applies to you, and how to avoid penalties. 

What is a Self-Assessment tax return?‘

“Those who earn over a certain amount of money each year are required to pay tax. Tax is usually deducted from an individual’s wage or pension automatically; however, those in receipt of other forms of income, including property and self-employment, will need to report their earnings to HM Revenue and Customs (HMRC) through a Self-Assessment tax return.”

Do I need to complete a Self-Assessment tax return?

“You will need to submit a Self-Assessment tax return if, during the last tax year between April 6, 2023, and April 5, 2024, you:

  • Were a partner in a business partnership; 
  • Had an overall taxable income of more than £150,000; 
  • Were classed as a self-employed sole trader and earned more than £1,000 before taking off anything you can claim tax relief on; 
  • Were required to pay the High Income Child Benefit Charge; 
  • Had to pay Capital Gains Tax, as a result of selling or disposing of something with an increased value; and/or 
  • Have untaxed earnings, such as tips, commission, foreign income, payments generated from renting out a property, or income from savings and investments.

“If you’re unsure whether any of the above apply to you, you can use this handy tool on the Gov.uk website to check whether you need to send a tax return. It’s better to check, rather than miss the deadline and be hit with an unexpected penalty further down the line.” 

Where can I find the relevant paperwork to complete my Self-Assessment tax return?

“You can file your tax return online, or call HM Revenue and Customs and ask for a paper version of the form, known as a SA100.’ Dan adds, ‘Be sure to familiarise yourself with any possible call charges before you phone.”

When is the Self-Assessment tax return deadline?

“If you choose to do a paper Self-Assessment return, this will need to be submitted before midnight on October 31, 2024. You have slightly longer to file online returns; these must be submitted before midnight on January 31, 2025.  ‘

“It might be an idea to set yourself a calendar reminder to avoid the risk of paying a penalty,” Dan suggests. 

Where should I send my Self-Assessment tax return?

You should send your completed Self-Assessment tax return paper form to the following address:  Self Assessment HM Revenue and Customs BX9 1AS United Kingdom. 

What happens once I’ve submitted my return?

“HMRC will use your report to calculate how much you owe. Your individual Income Tax band will be taken into consideration, and there’s also a different rate for Capital Gains Tax. Your Self-Assessment bill must be paid before January 31, 2025.” 

Is there anything else I need to know about the Self-Assessment tax return deadline?

“It’s important to be aware that missing deadlines will usually result in a penalty. If your tax return is up to three months late, you will be charged a £100 penalty for delayed filing. You’ll also end up paying more, and will be charged interest on any late payments.

“Depending on the circumstances, you might be able to appeal against a penalty. There are several reasonable excuses that may permit you to appeal, including postal delays out of your control, the death of a partner or close family member shortly before the tax return or payment deadline, and issues with the HMRC online services. You can view a full list of reasonable excuses on the Gov.uk website.”