Self assessment tax returns, what you need to know

Melanie Richardson


We are fast approaching the self assessment tax return deadline. If you are self employed or in receipt of other income or gains, you will need to file a return and pay over your tax liability. This article will discuss who needs to complete and file a self assessment tax return, when it needs to be completed by and the penalties for late submission. Don’t forget we, as your accountants are only a phone call away and always ready to help.


Who needs to file a self assessment tax return?

You will most likely have to file a tax return if you are:


  • Self employed and earning over £1,000 a year
  • A company director
  • Earning over £100,000 a year
  • In receipt of savings or investment income of more than £10,000 a year before tax
  • In receipt of income from abroad
  • Are the highest earner in a family claiming child benefit if you earn over £50,000
  • Earning £2500 or more in untaxed income (for example renting out a property, or in tips and commissions)


If you are still unsure whether you need to file a self assessment tax return, you can use this tool to find out


Tax return deadlines

There are two ways to complete your tax return for the year ended 5 April 2020; online or on paper. The deadline for paper returns of 31 October has already expired and the deadline for online returns is 31 January 2021.


Payment of tax due for the year ended 5 April 2020 should be made by midnight on 31 January 2021.


Late submission of self assessment tax return / paying your tax bill

You’ll get a penalty of £100 if your tax return is up to 3 months late. You’ll have to pay more if it’s later, or if you pay your tax bill late. You’ll also be charged interest on late payments.


You can work out any penalties due using this link


How to submit your tax return

If you haven’t already, you will need to register with HMRC to create an account and obtain your unique taxpayer reference number (UTR).


There are different ways to register if you are:


  • Self employed or a sole trader:


  • Not self employed but earn over £100,000


  • A partner in a partnership


Once you have registered (which can take up to 20 days) you can then use the online portal to complete and submit your tax return:



What information will you need to complete your form?

You will need your paperwork from the relevant year to complete your submission.


This may include:

  • A P60 form from your employer (if you have one) showing income and the tax you’ve already paid
  • A P45 if you have left a job in the current year
  • A P11D or P9D showing any benefits and expenses
  • A summary of any rental income and expenses
  • Savings and investment statements showing interest earned and other dividends
  • Documents detailing self employment income, including receipts, bank statements and accounts


How to pay your tax bill

You must pay your tax bill by midnight on 31 January. You can send the amount owed to HMRC by bank transfer, or by debit card (you can no longer pay your tax bill by credit card).


You can also send a cheque in the post, or pay at a bank by using a paying in slip from HMRC if you have received one.


Having issues?

If you are having issues with your self assessment tax return, please do get in touch with Robin Stevenson our tax partner and we can help you complete your tax return.


Robin tax partner swindells east sussex accountants and tax advisors


Robin Stevenson - Tax Partner


Tel: 01825 763 366

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