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What is an SA100 Form?

Updated: Dec 26, 2023

The SA100 form, widely recognized as the Self Assessment tax return, is an integral document for tax reporting in the United Kingdom, primarily used by individuals whose tax affairs are more complex than the standard PAYE (Pay As You Earn) system. This form is essential for those whose income is not fully taxed at the source or who have various income streams that necessitate a more detailed tax assessment.

Individuals who typically need to complete the SA100 form include the self-employed, company directors, those with significant investment income, people earning foreign income, and those with rental or other property income. Additionally, it's also used by individuals who are entitled to claim certain tax deductions or reliefs that aren't automatically processed through the PAYE system.

What is an SA100 Form?

For taxpayers in the United Kingdom, navigating the tax system can be a daunting task due to the numerous forms and regulations in place. One of the most important forms is the HMRC SA100, which is central to the Self Assessment process. This article will discuss the purpose of the SA100 form, who should use it, how to complete it, and the deadlines for submission.

The Importance of HMRC SA100 Form

The SA100 form comprehensively covers all aspects of an individual's income and tax deductions. It includes sections for reporting income from employment, self-employment, interest, dividends, pensions, and foreign income. Moreover, it allows for the declaration of various tax reliefs, such as those related to charitable donations or pension contributions, which might not be automatically accounted for in the PAYE system.

By filing an SA100, taxpayers provide HMRC with a complete picture of their taxable income and any allowances or deductions they are entitled to, ensuring a precise assessment of their tax liability. It is a key tool in the UK's tax system for ensuring that individuals pay the correct amount of tax according to their diverse and multifaceted financial circumstances.

Who Needs An SA100 Form?

You must file a form SA100 (tax return) if you are:

● Self-employed

● A company's director

● Earn an annual income of £100,000 or more

● Income from savings, investments or real estate

● Plan to ask for expenses or help

● Receipt of child benefit and income over £50,000

● foreign income receipt

● Payment of Capital Gains Tax

If you still don't know how to fill out a sa100 form, or if you need to fill one out, you can contact us at Pro Tax Accountant.

Where Can I Find the SA100 Form?

You can choose to submit your SA100 form on paper or online. Online is by far the easiest and fastest way to file your taxes.

Online – Filing your tax return online is so much easier and better than printing pages and pages. All you have to do is create an account with HMRC, add your income and expenses, and click submit. Their intelligent software searches page after page of information for you and updates all calculations instantly.

Paper – If for any reason you prefer to submit your SA100 form on paper, that is also an option. You can download the SA100 form from the HMRC website, but remember to apply for your UTR at least 6 weeks before your tax deadline. Without a UTR you cannot file a return and will be fined.

Who Should Use the SA100 Form?

The SA100 form is required for a range of taxpayers with various sources of income. You should use the SA100 form if any of the following situations apply to you:

  • You are self-employed or a sole trader, and your annual income is above the tax-free threshold.

  • You are a company director, a minister of religion, or a member of a partnership.

  • You have income from renting out property in the UK or overseas.

  • You have foreign income, capital gains, or other complex tax affairs.

  • You receive taxable income from savings, investments, or dividends.

  • You are a trustee, executor, or administrator of an estate.

  • You have untaxed income that cannot be collected through PAYE.

  • If you are unsure whether you need to complete the SA100 form, you can visit the HMRC website for guidance or consult a tax professional.

How to Complete the SA100 Form?

The SA100 form comprises various sections that require taxpayers to provide detailed personal and financial information. Here is an overview of the main sections of the form:

  1. Personal Details: Provide your full name, address, National Insurance number, and Unique Taxpayer Reference (UTR) number in this section.

  2. Income: Declare all sources of taxable income, such as employment, self-employment, pension, rental property, and investment income. You may need to complete supplementary pages (such as SA102, SA103, SA105, or SA106) depending on the type of income you receive.

  3. Tax Reliefs and Deductions: List any tax reliefs or deductions you are claiming, such as the Personal Allowance, Married Couple's Allowance, or allowable expenses.

  4. Tax Calculation: Calculate your total taxable income, tax liability, and any tax already paid or withheld. This section may require the completion of additional calculation pages, such as the SA110 Tax Calculation Summary.

  5. Declaration: Sign and date the form, confirming the accuracy of the information provided.

When to Submit the SA100 Form

The deadline for submitting your SA100 form depends on whether you choose to file a paper return or submit it online. For the tax year ending on April 5th, you must submit your paper SA100 form by October 31st of the same year. If you opt to file online, you have until January 31st of the following year to submit your form. It is essential to meet these deadlines, as late submissions can result in penalties.

A Step-by-Step Guide to Submitting the HMRC SA100 Form in the UK

Filing a tax return can be a complex and time-consuming process for many taxpayers in the United Kingdom. The HMRC SA100 form, or the Self-Assessment tax return form, is a crucial part of this process. To make the task of submitting your SA100 form easier, this article offers a step-by-step guide on how to prepare and submit your tax return, including registration, form completion, and submission options.

1: Registering for Self-Assessment

Before you can submit your SA100 form, you must first register for Self-Assessment with HM Revenue and Customs (HMRC). Here are the steps to register:

Determine if you need to register: Ensure that you are required to complete the SA100 form based on your tax situation. Refer to the guidelines provided by HMRC or consult a tax professional if you are unsure.

Register online: Visit the HMRC website and follow the instructions to register for Self-Assessment. You will need to provide your personal details and information about your income sources.

Obtain your Unique Taxpayer Reference (UTR): After registering, HMRC will issue you a UTR, a 10-digit number unique to you. Keep this number safe, as you will need it to complete and submit your SA100 form.

Activate your online account: You will receive an activation code by mail from HMRC, which you need to use to activate your online account. You must do this within 28 days of receiving the code.

2: Completing the SA100 Form

Once registered, follow these steps to complete your SA100 form:

Gather necessary documents: Collect all relevant documents, such as P60, P45, P11D, bank statements, invoices, receipts, and records of income and expenses.

Access the form: You can either download the SA100 form from the HMRC website or use commercial tax software that supports Self-Assessment.

Complete the form: Fill in your personal details, declare your income, claim tax reliefs or deductions, and calculate your tax liability. Make sure to complete any supplementary pages required for your specific income sources (e.g., SA102 for employment income, SA103 for self-employment income, etc.).

Review the form: Double-check your entries for accuracy and completeness, ensuring that you have included all relevant information.

3: Submitting the SA100 Form

You have two options to submit your SA100 form: by paper or online. Here are the steps for each method:

Paper submission:

a. Print the completed SA100 form and any supplementary pages.

b. Sign and date the declaration at the end of the form.

c. Mail the form to the appropriate HMRC office. You can find the correct address on the HMRC website or in the guidance notes provided with the form.

d. Submit the form by the paper filing deadline, which is October 31st following the end of the tax year.

To get a paper version of the form, you will have to call HMRC at the following numbers:


0300 200 3610

Outside UK:

+44 161 930 8331

Or write to them on:

If you live in the UK send to:

Self Assessment

HM Revenue & Customs


United Kingdom

If you live outside the UK send to:

HM Revenue & Customs

Benton Park View

Newcastle Upon Tyne

NE98 1ZZ

United Kingdom

Online submission:

b. Access the Self-Assessment section and select the option to complete your tax return online.

c. Enter the information from your completed SA100 form into the online version of the form, ensuring all details are correct.

d. Submit the form electronically by the online filing deadline, which is January 31st following the end of the tax year.

4: Paying Your Tax Liability

After submitting your SA100 form, you must pay any tax you owe to HMRC. The payment deadline is the same as the online submission deadline: January 31st following the end of the tax year.

How to Complete Different Sections of the SA100 Form

How to Complete Different Sections of the SA100 Form

Completing the UK Self Assessment tax return (SA100 form) requires attention to detail and accuracy. This guide will provide a detailed walkthrough of each section, addressing the questions and suggesting possible answers where applicable.

1. Personal Information and Preliminary Details

  • Unique Taxpayer Reference (UTR): Your 10-digit UTR as registered with HMRC.

  • National Insurance number (NINO): Enter your NINO in the format 'AB123456C'.

  • Name and Address: Provide your full name and current address.

  • Date of Birth: Enter your date of birth in the format DD/MM/YYYY.

  • Telephone Number and Email Address: Optional but recommended for efficient communication.

2. Declaration and Signing

  • Agreement to the Declaration: Before signing, ensure all information is accurate as this is a legal declaration of your financial affairs.

3. Income Sections

  • Employment Income (pages E1 to E4)

    • Employer’s Name and Address: The official name and address of your employer.

    • PAYE Reference: Found on your P60 or payslips, usually in the format '123/AB456'.

    • Employment Income: The total income from your employment, found on your P60.

    • Benefits and Expenses: Details of any benefits-in-kind or expenses from employment, usually on your P11D form.

  • Self-Employment (pages SE1 to SE4)

    • Business Name and Type: The name of your business and the nature of the trade.

    • Date Business Commenced/Ended: If applicable, the date you started or ceased trading.

    • Total Income and Expenses: Report your total business income and allowable expenses.

  • UK Property Income (pages UKP1 to UKP4)

    • Address of Property: Location of the rented property.

    • Total Rent Received: The total amount of rent received during the tax year.

    • Allowable Expenses: Expenses incurred for the property, like repairs or agent fees.

  • Foreign Income (pages F1 to F9)

    • Type of Foreign Income: Specify the type of income, e.g., employment, business.

    • Amount of Income Before Tax: The gross amount received from foreign sources.

    • Foreign Tax Paid: Any foreign tax paid on the income.

4. Interest and Dividends

  • Interest from UK Banks (pages AI 1)

    • Amount of Untaxed UK Interest: Interest received that wasn’t taxed in the UK.

    • Amount of Taxed UK Interest: Interest that has already been taxed.

  • Dividends (pages AI 2)

    • UK Dividends: Total dividends from UK companies.

    • Foreign Dividends: Dividends from non-UK companies.

5. Pensions, Annuities, and State Benefits (pages Pen 1)

  • State Pension: Total amount of State Pension received.

  • Other Pensions and Retirement Annuities: Details and amounts of other pensions.

  • Taxable Incapacity Benefit: If applicable, the amount received.

6. Capital Gains Tax (pages CG 1 to CG 4)

  • Disposals: Details of assets sold, like property or shares.

  • Gains and Losses: Calculate the gain or loss from each disposal.

7. Additional Information (pages Ai 1 to Ai 4)

  • Married Couple's Allowance: If applicable, provide details of your marriage or civil partnership.

  • Blind Person’s Allowance: If eligible, indicate this for an additional allowance.

  • Life Insurance Gains: Report any chargeable event gains from life insurance policies.

  • Tax Avoidance Schemes: If you've used any disclosed tax avoidance schemes, provide the scheme reference number.

8. Tax Reliefs and Deductions

  • Pension Contributions (pages TR 3 to TR 4): Amount paid into registered pension schemes, excluding employer contributions.

  • Charitable Donations (pages TR 3 to TR 4): Details of Gift Aid donations and other charitable contributions.

  • Maintenance Payments: If you make qualifying maintenance payments, provide the amount.

9. High Income Child Benefit Charge (pages HICBC 1)

  • Adjusted Net Income: Calculate your adjusted net income to determine if it exceeds £50,000.

  • Child Benefit: The amount of Child Benefit received, if your income exceeds £50,000.

10. Student Loan and Postgraduate Loan Repayments (pages SL 1 to SL 2)

  • Student Loan Plan Type: Identify whether you’re on Plan 1, Plan 2, or the Postgraduate Loan plan.

  • Repayments: State the amount of repayments made during the tax year.

11. Incorrectly Claimed Coronavirus Support Scheme Payments

  • Details of Overclaimed Amount: If you've received overpayments from schemes like the Coronavirus Job Retention Scheme or the Self-Employment Income Support Scheme, declare the amount.

12. Marriage Allowance

  • Transferor/Recipient Details: If you're transferring or receiving a portion of your Personal Allowance to or from a spouse, provide the relevant details.

13. Additional Pages

  • Supplementary Pages: Depending on your circumstances, you may need to complete additional sections like SA102 for employment, SA103 for self-employment, SA105 for UK property income, etc.

14. Final Checks and Submission

  • Accuracy Check: Revisit each section to ensure all information is accurate and complete.

  • Sign and Date: Don't forget to sign and date the declaration on page TR 8.

  • Submission: Choose whether to submit online or by post. Be mindful of the deadline.

15. Keeping Records

  • Documentation: Keep records of all income, expenses, benefits, and pensions for at least 22 months after the end of the tax year.

A Comprehensive Guide to the HMRC SA200 Form in the UK

The UK tax system can be complex, with different forms and regulations that taxpayers must adhere to. One such form is the HMRC SA200, which is crucial for certain taxpayers in the United Kingdom. In this article, we will explore the purpose of the SA200 form, who should use it, how to complete it, and the deadlines for submission.

What is the HMRC SA200 Form?

The HMRC SA200, also known as the Short Tax Return, is a simplified version of the Self-Assessment tax return form (SA100) designed for individuals with relatively simple tax affairs. This form allows eligible taxpayers to declare their income and calculate the amount of tax they owe to HM Revenue and Customs (HMRC) for a specific tax year. The SA200 is used as an alternative to the more comprehensive SA100 form, making the tax filing process easier and less time-consuming for those who qualify.

Who Should Use the SA200 Form?

The SA200 form is intended for individuals whose tax affairs are relatively straightforward. You might be eligible to use the SA200 form if you meet the following criteria:

  • Your total income for the tax year is below £100,000.

  • You receive income from employment or self-employment, pension, or interest, but not from property rental or a limited company.

  • You do not have any foreign income, capital gains, or other complex tax affairs.

  • You do not claim any tax reliefs or deductions, apart from the standard Personal Allowance or Blind Person's Allowance.

It is important to note that HMRC will notify you if you are eligible to use the SA200 form. If you do not receive a notice, you must complete the full SA100 form.

How to Complete the SA200 Form

The SA200 form is divided into several sections that require taxpayers to provide personal and financial information. Here are the main sections of the form:

Personal Details: In this section, you must provide your full name, address, National Insurance number, and Unique Taxpayer Reference (UTR) number.

Employment Income: Include details about your employment, such as your employer's name and address, your job title, and your gross salary.

Self-Employment Income: If you are self-employed, you must provide information about your business, including your business name, type, and total turnover.

Pension Income: Declare any pension income you receive from the UK, including state pensions and private pensions.

Interest Income: Include any interest earned from a bank or building society accounts, as well as other taxable interest.

Tax Deductions: List any deductions you are claiming, such as the Personal Allowance or Blind Person's Allowance.

Tax Calculation: The form provides a simple calculation to determine your tax liability based on the information provided in the previous sections.

Declaration: Finally, you must sign and date the form to confirm the accuracy of the information provided.

When to Submit the SA200 Form

The deadline for submitting your SA200 form is the same as the SA100 form. For the tax year ending on April 5th, you must submit your paper SA200 form by October 31st of the same year, or by January 31st of the following year if you file online. Late submissions can result in penalties, so it is essential to meet these deadlines.


The HMRC SA200 form is a simplified tax return form designed for individuals with less complex tax affairs. By understanding the eligibility criteria, how to complete the form, and the submission deadlines, you can ensure you meet your tax obligations in time.

Why It Is a Good Idea to Get Professional Help for HMRC Sa100 and Sa200 Forms

Why It Is a Good Idea to Get Professional Help for HMRC Sa100 and Sa200 Forms?

The Benefits of Professional Assistance for HMRC SA100 and SA200 Forms

Tax season in the United Kingdom can be a stressful time for many taxpayers, especially when navigating the complexities of Self-Assessment. The HMRC SA100 and SA200 forms are essential components of the tax filing process, and ensuring their accurate completion is crucial to avoid penalties and maximize tax efficiency. This article will discuss the benefits of seeking professional help when dealing with SA100 and SA200 forms in the UK and the advantages they can offer.

Ensuring Accurate Tax Reporting

One of the main reasons to seek professional assistance with your SA100 and SA200 forms is to ensure accurate tax reporting. Tax professionals, such as accountants and tax advisors, have the expertise to:

Identify all sources of income: They can help you accurately declare all your income, including employment, self-employment, rental property, and investment income, reducing the risk of under-reporting.

Claim eligible tax reliefs and deductions: Professionals can identify and correctly apply all relevant tax reliefs, deductions, and allowances that you may be eligible for, ensuring that you pay the correct amount of tax.

Avoid errors and omissions: Tax professionals have the experience and knowledge to spot and correct errors or omissions in your tax return, minimizing the risk of penalties from HMRC.

Saving Time and Reducing Stress

Another significant advantage of seeking professional help with your SA100 and SA200 forms is the time saved and reduced stress associated with tax filing. Tax professionals can:

Complete the forms efficiently: Their expertise allows them to fill out the forms quickly and accurately, freeing up your time for other personal or business tasks.

Handle complex tax situations: Professionals are well-equipped to manage complex tax affairs, such as foreign income, capital gains, or multiple income sources, ensuring your tax return is completed correctly.

Communicate with HMRC on your behalf: In case of queries, disputes, or issues with your tax return, tax professionals can liaise with HMRC on your behalf, alleviating the stress of dealing directly with the tax authority.

Staying Compliant with Tax Laws and Regulations

Tax laws and regulations in the UK are constantly evolving, and staying up-to-date with these changes is vital to ensure compliance. By seeking professional help with your SA100 and SA200 forms, you can:

Keep up with changes in tax laws: Tax professionals stay current with the latest tax laws and regulations, ensuring that your tax return complies with the most recent requirements.

Avoid penalties and interest: Professionals can help you meet filing deadlines and avoid penalties, interest, and potential tax investigations by ensuring your tax return is submitted on time and accurately.

Receive expert advice on tax planning: Tax professionals can provide strategic advice on tax planning and minimization, helping you make informed decisions to optimize your tax position in the long term.

Maximizing Tax Efficiency and Savings

Lastly, seeking professional help with your SA100 and SA200 forms can lead to increased tax efficiency and potential savings. Tax professionals can:

Identify tax-saving opportunities: They can help you take advantage of tax-saving strategies and opportunities, such as tax-efficient investments, pension contributions, or business expense claims.

Optimize your tax position: Professionals can analyze your overall tax situation and suggest ways to optimize your tax position, potentially resulting in reduced tax liabilities.

Provide tailored tax advice: Tax professionals offer personalized advice based on your individual circumstances, ensuring that you receive guidance tailored to your specific needs and goals.


In conclusion, seeking professional help for HMRC SA100 and SA200 forms in the UK offers numerous benefits, including accurate tax reporting, time savings, peace of mind etc.

25 Most Important FAQs about "SA100 form"

Q1: What is the SA100 form used for in the UK?

A: The SA100 form is used for filing an individual's Self Assessment tax return, detailing income, capital gains, and claiming allowances and reliefs.

Q2: Who needs to complete an SA100 form?

A: It's required for individuals who are self-employed, have significant savings or investment income, earn income from property, or have other income not taxed at source.

Q3: Can I file the SA100 form online?

A: Yes, the SA100 form can be filed online through HMRC's website, which is often faster and more convenient than paper filing.

Q4: What is the deadline for submitting the SA100 form?

A: The deadline for online submission is January 31st following the end of the tax year. For paper submissions, it's October 31st.

Q5: What are the penalties for late submission of the SA100 form?

A: Late submission can result in penalties starting at £100, increasing over time and depending on the delay's duration.

Q6: How do I register for Self Assessment to get an SA100 form?

A: You can register online through the HMRC website. Once registered, you'll receive a Unique Taxpayer Reference (UTR) number.

Q7: What information do I need to complete the SA100 form?

A: You'll need details of your income, including employment income, dividends, interest, and any capital gains, as well as allowable expenses.

Q8: Can I amend my SA100 form after submission?

A: Yes, amendments can be made within 12 months of the original submission deadline.

Q9: How does the SA100 form differ for self-employed individuals?

A: Self-employed individuals must complete additional supplementary pages detailing their business income and expenses.

Q10: What are the common mistakes to avoid when filling out the SA100 form?

A: Common mistakes include incorrect income figures, not declaring all income sources, and miscalculating tax owed.

Q11: Is professional help required to complete the SA100 form?

A: While not mandatory, seeking professional help can be beneficial, especially for complex tax situations.

Q12: How does marriage or civil partnership affect the SA100 form?

A: Being in a marriage or civil partnership can affect your tax allowances and the amount of tax you owe, which should be reflected in your SA100.

Q13: What are payments on account and how are they reported on the SA100 form?

A: Payments on account are advance payments towards your tax bill and are calculated based on your previous year's tax bill.

Q14: How do I claim tax reliefs or allowances on the SA100 form?

A: You can claim tax reliefs or allowances in the relevant sections of the SA100 form, depending on the type of relief or allowance.

Q15: What is the significance of the UTR number in the SA100 process?

A: The UTR number is essential for identifying your tax records and is required when submitting your SA100 form.

Q16: How do I report foreign income on the SA100 form?

A: Foreign income is reported in the foreign section of the SA100 form, and you may need to fill out additional supplementary pages.

Q17: What to do if I made a loss in my business or investments?

A: Report any losses in the business or capital gains sections of the SA100 form, as these can affect your tax calculation.

Q18: Can I use the SA100 form to report income from property rental?

A: Yes, income from property rental is reported on the SA100 form, along with any allowable expenses related to property maintenance.

Q19: What is the role of National Insurance Contributions in the SA100 form?

A: National Insurance Contributions are calculated based on your earnings and must be reported on the SA100 form if you're self-employed.

Q20: How do I handle dividends and interest from shares on the SA100 form?

A: Dividends and interest from shares are reported in the respective sections of the SA100 form, and you may have tax liabilities depending on the amount and your tax band.

Q21: What is My UTR?

UTR stands for Unique Tax Reference. This code is unique to your company and will be used as a reference when contacting HMRC. UTR stores all tax information related to your company. It must be kept in a safe and accessible place for you and your tax accountant.

Q22: Where can I Get My UTR Number?

When you register for your tax return, HMRC will give you a UTR number.

If you are already registered, your UTR may appear on many HMRC documents, including:

● SA250 form or your "Self-Assessment" letter

● payment reminder

● your tax return

● Your user account information

● You can also retrieve it from your personal account on the HMRC website.

SA100 Form

23: How to Pay Tax Owed Through Self-Assessment?

When completing an SA100, you must indicate how much you earned in the previous tax year. Depending on your situation and your reasons for completing the form, you may also need to provide details of any other income you have received.

HMRC will then calculate the amount of income tax and national insurance you will have to pay and tell you how and when to pay it. This can usually be done by bank transfer or with a debit card.

24: When Should I File an SA100 Form?

The deadline for paper tax returns is October 31 of each year, but the deadline for online tax returns (SA100) is January 31.

So, hopefully, our detailed information on the SA100 form has cleared up any confusion surrounding this area of self-assessment

25: Where to Find Help with Your Taxes?

There are various help sheets available on the HMRC's website and you can also call them directly if you have any questions. There are several free, independent charities, such as Citizens Advice, that you can contact for help with your tax return.

If you have decided to seek the help of a tax advisor, the PTA can complete the form for you.


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