Self-assessment tax return

What is a self-assessment tax return?

A tax return is a form that must be submitted to HM Revenue & Customs, declaring all of your income that is taxable in the UK, claims for tax reliefs, and the tax payable. The period for which you report these is 6 April to 5 April (the tax year); for the 2017/18 tax return, this will be 6 April 2017 to 5 April 2018.

When to submit?

The deadline to submit this to HM Revenue & Customs is:

If submitting electronically
  • 31 January following the end of the tax year, or
  • 3 months from the date you are issued a tax return
If submitting by post
  • 31 October after following end of the tax year, or
  • 2 months from the date you are issued a tax return

The deadline to pay any tax due is 31 January after the end of the tax year regardless of the method of submission.

The declaration is self-assessed, so it is up to you to ensure that you have correctly completed the tax return. It is also your responsibility to inform HM Revenue & Customs if you need to complete a tax return, but one has not been issued to you. The deadline to inform HM Revenue & Customs is 5 October following the end of the tax year.

Who needs to complete one?

You will need to complete a tax return if:
  • You are a company director
  • You are a partner in a partnership
  • You are self-employed and your turnover is more than £1,000
  • You receive rental income of more than £2,500
  • You’ve received other untaxed income of more than £2,500
  • You’ve investment income (including bank interest and dividend income) which exceeds £10,000
  • Your income (or your partners) was over £50,000 and one of you claimed Child Benefit
  • Your total income exceeds £100,000
  • You have Capital Gains (or Losses) to declare

This content was contributed by Alliotts Chartered Accountants & Business Advisors.