SA100 is the name of the main tax return form used in the UK for individuals to report their income, claim tax reliefs, and calculate their tax liability for a tax year. Individuals who need to file a UK Self Assessment tax return typically use the SA100 form.

Who Needs to File

You may need to file SA 100 for Self Assessment tax return if you fall into one of the following categories:

  • Self-employed or a sole trader with income above a certain threshold.
  • A company director.
  • Receiving income from renting out a property.
  • Receiving significant income from savings, investments, or dividends.
  • Earning over a certain level of income (thresholds change each tax year).
  • Receiving foreign income.
  • You or your partner’s income exceeds a certain level and you are claiming Child Benefit.
  • Your income is over £100,000.
  • You have Capital Gains Tax to pay.
  • You need to claim tax reliefs or deductions.

Tax Year

The UK tax year runs from April 6th to April 5th the following year. For example, the tax year 2023-2024 runs from April 6, 2023, to April 5, 2024.

Filing Deadline

The deadline for filing a paper SA100 tax return is typically October 31st following the end of the tax year. However, if you file your tax return online, you have until January 31st of the following year to submit it.

Online Filing

HM Revenue and Customs (HMRC) encourages online filing as it provides additional benefits, such as automatic calculations and instant acknowledgement of receipt.

Supplementary Forms

In addition to the main SA100 form, you may also need to complete supplementary forms (SA101 to SA107) if you have specific types of income or need to claim certain reliefs or allowances.

Payment of Tax

If you owe tax after completing your Self Assessment, the payment deadline is January 31st following the end of the tax year. This is also the deadline for any balancing payment and the first payment on account for the next tax year.

It is important to keep accurate records of your income, expenses, and any other relevant financial information to ensure that you accurately complete your Self Assessment tax return. If you are unsure about your tax obligations or how to complete the SA100 form, it’s advisable to seek guidance from a qualified tax professional or contact HMRC for assistance.