In the UK, individuals and certain entities are required to submit self-assessment tax returns to HMRC, declaring their income, expenses, and profits. Limited companies, however, file Corporation Tax returns (CT600) instead of self-assessment tax forms. The self-assessment forms help taxpayers ensure they are paying the correct amount of tax on their financial activities during a tax year. This guide allows taxpayers to understand the various HMRC self-assessment forms they may need to complete, depending on their specific situation.
The following are some of the important and common forms individuals and company directors use to file their self-assessment tax returns:
SA100: Main Self-Assessment Tax Return Form
The SA100 form is the main self-assessment tax return used by HMRC to calculate individuals’ tax liabilities. Hence, any taxpayer who is required to report their taxable income to HMRC through Self-Assessment will complete the key SA100 form to achieve this.
The SA100 tax return form comprises eight pages. It collects the necessary tax details, including total income, investments, dividends, pension income (if applicable), annuities, state benefits and Gift Aid (if applicable).
Taxpayers’ tax payments can vary based on their individual circumstances and income sources. Thus, they might need to submit additional SA100 supplementary pages to report their taxable income accurately to HMRC.
Submitting a self-assessment tax return online is a more streamlined, convenient process, with 97% of taxpayers choosing this method. To learn how it is done, read:
SA102 – Employment
The SA102 form comprises supplementary pages appended to the primary SA100 tax return and is a mandatory inclusion for individuals opting to submit paper-based tax returns.
Taxpayers use these supplementary pages to record the details and inform HMRC more about the income they receive if they:
- Work for an employer who deducts their due tax under the PAYE system
- Are working and receiving income as a limited company director
- Need to claim their employment expenses, given that the employer has not reimbursed them already
- Hold the office of a chairperson, secretary, or treasurer in an organisation and receive a salary for their position
- Work for someone via a partnership or another company
- Receive foreign income from employment, directorship, or an office
A separate SA102 form is not needed for online self-assessment tax returns, as it is already included in the digital submission.
SA103 – Self-Employment
The SA103 forms, SA103S and SA103F, are supplementary tax return forms that the self-employed (sole traders) fill out to record details of their self-employment income on the main SA100 self-assessment.
An individual will complete the SA103S (short) if their annual business turnover was below the VAT threshold for the tax year (£90,000 for the tax year 2025/26). The self-employment (short) form is generally used by business owners running a simple or small-scale business.
Self-employed individuals with larger, relatively complex businesses complete the SA103F or Self-employment (full) supplementary pages if they meet any of the following criteria.
- Their annual business turnover exceeds £90,000.
- They need to adjust the business’s profits or losses for the accounting period if they have changed the accounting date. For instance, the accounting period either ended before 31 March 2025, was less than 12 months, or did not end in the tax year.
- They need to adjust their income if they have changed their accounting basis.
- They need to manually adjust the profits, which are subject to Class 4 NICs, because their taxable income and the NIC-applicable profits vary. This way, they ensure their income tax and NICs are calculated correctly.
As a taxpayer, you must know the important deadlines for filing their tax returns and avoid HMRC penalties:
SA800 – Partnership Tax Return
When two or more individuals run a business by choosing a partnership structure in the UK, it is vital to file an SA800 self-assessment form every year. Regardless of the partnership’s profitability, this form must be submitted and is filed by the partnership itself, rather than by individual partners.
SA104 – Business Partnership
In addition to the partnership submitting its tax return, each partner is also obligated to file an individual tax return using the SA104 form. It is to report their individual share of income, profits, or losses.
Notably, the SA104 has two variants: SA104(short) and SA104(full)
The SA104S is used to report the short version of income on the main tax return, such as when the income and deductions are simpler and less information is needed.
In contrast, a partner will file the SA104 (Full) supplementary pages when the partnership circumstances are not straightforward, requiring thorough details of income, deductions and expenses.
SA105 – UK Property Income
If an individual owns property in the UK and earns income from it, they must complete the SA105 form to determine their tax bill. The HMRC SA105 form is the supplementary page an individual uses to report their property and land income alongside their main self-assessment tax return. Importantly, a person must fill the SA105 or UK property pages form if they receive income from:
- Renting out residential or commercial property/land in the UK.
- Furnished Holiday Lettings (FHL) in the UK or European Economic Area (EEA).
- Letting furnished rooms in their own home.
- Premiums arising from leasing UK land.
SA106 – Foreign Income
If an individual is a UK tax resident but also receives additional income from sources outside the UK, they will submit the SA106 form. UK residents complete the SA106 supplementary form to record and pay tax on various types of foreign income and gains that they cannot fully report on the main SA100 tax return form. Notably, types of foreign income and gains that a person can report on SA106 include:
- Interest from overseas savings.Â
- Dividends received from foreign companies.Â
- Remitted foreign savings income.
- Remitted foreign dividend income.Â
- Income earned from overseas pensions.Â
- Income received from overseas land and property.
- Foreign tax paid on employment, self-employment, and other income.
SA107 – Trusts
In the scenario where an individual receives an income from a trust, settlement or a deceased person’s estate, they must attach the supplementary pages of the SA107 form to their SA100 tax return to show their income.
Additionally, trusts are highly effective in safeguarding assets and managing them. There are different types of trusts, each serving a beneficial purpose. Learn how to establish one:
SA900 – Trust and Estate
The SA900 form requires trustees or personal representatives to submit details of income, capital gains, and tax liability arising from the trust or property.
SA970 – Trustee Of A Registered Pension Scheme
The SA970 is another important form among HMRC self-assessment forms, which is specifically for the trustees of a registered pension scheme to report the details of their pension income and gains, and pay the tax due through paper submission. It is relevant to mention that HMRC is not currently accepting SA970 online returns. Therefore, the individuals must complete and submit a paper tax return to HMRC.
SA108 – Capital Gains Tax
The SA108 is an HMRC self-assessment form used to submit the details of capital gains and losses. When an asset (whose value has increased) is sold or disposed of for profit, it can trigger the liability of Capital Gains Tax (CGT).
Now, when an individual is required to pay CGT, they will report their capital gains and losses during the tax year via the SA108 form, often referred to as the Capital Gains Summary.
Fortunately, there are Capital Gains Tax reliefs available to individuals, which they can claim to reduce their CGT. Refer to the following guide to learn more:
SA109 – Non-Residence
Non-UK residents earning income in the UK (e.g., overseas landlords) are taxed by HMRC solely on their UK earnings. UK residents who are not UK-domiciled can opt for the remittance basis, paying tax only on overseas earnings brought into the UK, for which the SA109 form is used.
Self Assessment
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SA700 – Non-Resident Companies
Non-resident companies previously used HMRC Form SA700 for paying income tax. However, from April 2020, non-resident companies investing in UK property and earning income arising from it are now subject to Corporation Tax (CT600) and no longer use the SA700 for that income.
However, non-resident companies file SA700 and pay income tax at the basic rate if:
- It is not trading in the UK through a permanent establishment but earning income in the UK (not property income). Examples include UK interest, royalties, some UK commercial income not tied to property, and certain intangible income sourced to UK sales/services.
- It is trading in the UK through a permanent establishment but has income arising in the UK, which is not tied to a permanent establishment through which it is carrying out its trade.Â
SA101 – Extra Information
A person should use the SA101 tax return form when filing their SA100 Tax Return to report additional or less common types of income, deductions and certain tax reliefs. Moreover, the SA101 supplementary pages are also used to submit additional details about Income Tax losses, pension charges and tax avoidance schemes. Examples include government bonds, interest received from UK securities, and peer-to-peer (P2P) loans made via a UK platform.
SA102MP – Members Of Parliament
If a person is a Member of Parliament (MP) or holds the office of a minister, they should file the SA102MP supplementary pages. By using this form, they will report their parliamentary income on their SA100 Tax Return.
SA103L – Lloyds Underwriters
Individuals use the Lloyds Underwriters SA103L supplementary pages to record income, expenses, and losses as a result of their membership in Lloyd’s. Significantly, Lloyd’s functions as an insurance market; individuals utilise the SA103L form to report their trading outcomes as members on their SA100 tax return.
Conclusion
Filing tax returns is a crucial responsibility for every individual and business that conducts trading activities and earns profits. To make the process easier and facilitate the taxpayers, there are different HMRC self-assessment forms, each of which caters to taxpayers with different income sources and tax liabilities. However, turning to an expert can save you a great deal of effort and time. Fortunately, with professional self-assessment services at Clear House Accountants, you can never miss out on a self-assessment tax return deadline again.
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