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Self Assessment Tax forms form part of the Self Assessment tax return submission to HMRC.

There are a nine main Self Assessment tax forms (or supplementary pages) that you need to be aware of when completing your tax return. And unless you’re well acquainted with each, it’s easy to file your taxes incorrectly. We’ve summarised each of them below.

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Receive money from UK securities, deeply discounted securities or accrue income profits? You’ll need an SA101 form. It largely covers uncommon forms of income. These include:

  • Stock dividends
  • Gains from insurance policies
  • Government stocks, gilt-edged securities or gilts
  • Peer-to-peer loans using a UK platform

However, you won’t need to file an SA101 form if you receive income from an ISA or PEP.

You can find out more about SA101 forms here.


Whether you’re in full-time, part-time or casual employment, you’ll need to file an SA102 form alongside your Self Assessment tax return form. A separate ‘Employment’ page is required for each role you held within that tax year, You are considered to be in ‘employment’ if you:

  • Are working for an employer who deducts tax through PAYE
  • Are holding (and receiving income for) a chairperson, secretary or treasurer role
  • Are receiving income as a company director
  • Are receiving foreign income from a job, directorship or office
  • Had an outstanding balance on a disguised remuneration loan

When filing an SA102 form, you’ll be required to provide your P45, P65, and any employment expenses that may be relevant.

You can find out more about SA102 forms here.

SA103S and SA103F

If you’re self-employed, the SA103 forms are used to work out your Income Tax for the years you’ve been a sole trader. There are two versions: SA103S and SA103F. The former is shorter and designed for those with an annual turnover (or estimated annual turnover if you had traded for a full year) of less than £85,000 (as of 2020/21). You should only file an SA103F if you:

  • Have an annual turnover that exceeds £85,000
  • Have changed your accounting date
  • Are claiming Overlap Relief
  • Have adjustment income because you changed your accounting basis
  • Were within the Managing Serious Defaulters programme during the tax year

These are just a few of the reasons why you may need to file a long-form SA103 form.

You can find out more about SA103 forms here.


This form relates to the partnerships you’re involved in. You will need to fill out an SA104 if you were entitled to a share of the profits, losses or income from a business related to your partnership.

All partners are responsible for announcing their income related to the partnership. Should any fail to submit a Self Assessment tax return when they are required to, each partner may be subject to an automatic £100 penalty.

You can find out more about SA104 forms here.

It is worth noting that the ‘Partnership’ is also required to file a Self Assessment tax return, known as the SA800.


Landlord? Chances are you’ll need to fill out the SA105 form. This supplementary page of the Self Assessment tax return is for those who own property in the UK and have to pay Income Tax on it. This extends further than rental income though, and you may need to fill out one if you receive:

  • Income from letting furnished rooms in your own home
  • Income from Furnished Holiday Lettings in the UK or EEA
  • Premiums from leasing UK land

However, this UK property tax form is not for other foreign properties. For this, you’ll need the SA106 foreign tax form.

You can find out more about SA105 forms here.


The SA106 foreign tax form is for UK tax residents who need to pay tax on foreign income. You don’t need to include this form in your Self Assessment tax return if your income from property (including UK property) is less than £1,000 per year. However, if your income from land and property abroad does exceed this, you will be eligible. Likewise, you’ll also be eligible if you have:

  • Interest from overseas savings
  • Income from overseas pensions
  • Dividends from foreign companies
  • Foreign tax paid on employment, self-employment and other income

For foreign income earned by your business or partnership, you’ll want to use the SA101 form or, if applicable, the SA102 form.

You can find out more about SA106 forms here.


The SA107 form is for those who need to report income received from trusts, settlements, or a deceased person’s estate. You may also need to fill out an SA107 form if you:

  • Were a settlor and have put money or assets into a trust or settlement
  • Received or were entitled to income from a trust or settlement, excluding bare trusts
  • Were taxable on income arising to trustees of a settlor-interested trust
  • Were taxable on income payable to minor children from property in settlement

Depending on where your income is from, you may also need an R185 form to ensure you’re compliant.

You can find out more about SA107 forms here.

It is worth noting that the ‘Trust’ is also required to file a Self Assessment tax return, known as the SA900.


This supplementary page is for filing the residence and remittance elements of your Self Assessment tax return. You’ll need to fill this in if you are a non-UK resident, dual resident, or not ordinarily a resident or not domiciled in the UK.

However, you may also need to file if you:

  • Are eligible for overseas workday relief
  • Became a UK resident during the tax year
  • Have a domicile outside the UK

You can find out more about SA109 forms here.

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GoSimpleTax helps you fill in all the relevant forms. Our no-obligation free trial can be used to start inputting your income and expenditure, before working out how much tax you owe. To then file your completed Self Assessment tax return directly to HMRC, all you need to do is upgrade.

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