What is an SA109?

Do you keep hearing about the SA109 form but are not too sure what it is? You're in the right place. As a landlord or self-employed person in the UK, you may likely have heard about the form. But what exactly is it, and why do you need to deal with it? The SA109 is simply your Self-assessment tax return that needs to be filed each year to report your income and calculate how much tax you owe or are due back as a refund.

Arjun Kumar
Arjun Kumar
Jan 29, 2024
What is an SA109?

While the form itself isn’t the most exciting thing to fill out, understanding what it is and why it matters can help make the self-assessment process a little less painful. Keep reading to get the full scoop on everything SA109 so you can tackle your tax return with confidence.

What Is the SA109 Tax Form?

The SA109 is a supplementary tax form for filing the Residence and remittance basis tax pages of your self-assessment.

As a landlord, self-employed individual or expat, you'll need to fill out the SA109 to disclose earnings, profits or losses from the previous tax year ending April 5th. The form covers income from employment, pensions, savings, investments and property. You'll report total earnings for each category and claim any tax relief or deductions you're entitled to.

Based on the information provided, HMRC will determine if you've paid the correct amount of tax for the year or if you're due a bill or rebate. For non-resident landlords and expats, the SA109 requires you to disclose UK rental and business income even if you live abroad.

The self-assessment tax return online deadline is January 31st following the end of the tax year. You must submit the SA109 and pay any tax due by this date to avoid potential penalties.

How to Fill Out and Submit the SA109 Form

To fill out and submit the SA109 tax return form, here are the steps you'll need to take:

First, gather the necessary information, like your income statements, expenses, and other financial records from the tax year. You'll want everything handy so you can accurately report your earnings and claim any deductions or credits you're entitled to.

Then, go to HMRC website and download the SA109 form. You can print and fill it out manually. When the form is ready, you can also mail it to the address listed on the SA109. Otherwise, you can complete your self-assessment through an HMRC-recognised software, like Taxd, to make the process easier. With Taxd, you can be sure that you pay the least tax possible.

Whichever method you choose, be sure to keep records of your submission in case any issues are processing your return. The taxman will send you a statement showing your final tax bill or refund amount when they've reviewed and processed your SA109.

Tips for a Successful SA109 Submission

To successfully submit your SA109, keep these tips in mind:

Check Your Calculations

Double-check that all income, expenses, tax credits and other details have been reported accurately. Small mistakes can lead to penalties. Use tax return checklists and calculators to ensure everything adds up before you submit.

Pay Any Tax Due

If you owe tax, pay it by the January 31st deadline to avoid interest charges. You can pay via direct debit, bank transfer, over the phone, or with a cheque.

Keep Records

Keep copies of your SA109 and records of all income and expenses for at least six years. HMRC can review returns up to that long after submission. Good records will allow you to easily respond to any inquiries.

Get Help if Needed

Don’t hesitate to use the guidance on GOV.UK or Taxd if you need help. We can ensure your SA109 is completed properly and submitted on time.


So there you have it, the SA109 tax return form demystified. While doing your taxes is rarely an exciting task, understanding what’s required and the deadlines involved will help ensure you file accurately and avoid any penalties. The self-assessment process may seem complicated, but breaking it down step-by-step makes it much more manageable.

Remember, if you're struggling with the form, the Taxd online self-assessment tool allows you to effortlessly submit your tax return to HMRC.

Frequently Asked Questions

1. Can you file an SA109 form online?

You can’t file an SA109 form through HMRC. However, with Taxd, you can file the form online.

2. When do I need to use the SA109 form?

You should use the SA109 form when you have foreign income, gains, or losses to report on your UK tax return. It's necessary if you're a UK resident or have UK tax obligations.

3. How can I access the SA109 form for my UK tax return?

You can download the SA109 form from the official HM Revenue and Customs (HMRC) website or request it from your accountant if you use professional UK tax return services.

4. Do I need professional assistance for SA109 and UK tax return services?

Whether or not you need professional assistance depends on your circumstances. Many people complete their self-assessment and SA109 forms on their own, but some prefer the peace of mind and expertise of tax professionals to ensure accuracy and compliance with UK tax regulations.

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