Understanding the SA109 Form for Non-Residents
If you’ve always lived in the UK, then you’ll be taxed in the UK on your worldwide income. So, if you live in London and own a property in Spain and receive rental income, you’ll get taxed on that.

SA109 is a residency form that is part of the UK tax self-assessment. But before we look into its details, let us first understand a bit about UK residency.
If you’ve always lived outside the UK but earn income here, you will generally only be taxed on your UK-based earnings. For example, if you’ve lived in Spain your entire life and own a rental property in London, you’ll be liable to pay UK tax on the rental income from that property.
Lots of international agreements, known as tax treaties, are in place to help minimise the risk of being taxed twice.
From a tax point of view, there are two things that can affect how you’re taxed. First, where you are resident – if you are non-resident, then you will generally only be taxed on what you earn in the UK.
The other consideration is your domicile (usually where you were born) - if you’re not UK domiciled but live in the UK, then you can apply to only be taxed on money you bring to the UK - the “remittance basis.”
Are you a UK resident or not?
It’s important to know if you’re a UK resident or not. This may affect your UK tax liability and your entitlement to income tax allowances and exemptions.
If you are a non-UK resident, you will still have to declare income you receive from UK sources or gains you make from assets in the UK, and you may have to pay non-resident tax on them. This is done via SA109.
Residency tests apply to the tax year Statutory Residence Test (SRT), which runs from 6 April to 5 April. What is an SA109 form? SA109 is the residency form that is part of a self-assessment tax return. The SA109 is a supplementary tax form for filing the residence and remittance basis tax pages of your UK tax self-assessment. For the SA109 form, please click here. Do I need to submit an SA109 form? An SA109 is for individuals who:
- are not resident in the UK
- are not a UK resident but were prevented from leaving the UK because of COVID-19 and performed UK employment duties in the period they were unable to leave the UK
- are resident in the UK and:
are eligible for overseas workday relief (OWR) became a UK resident during this tax year are due split-year treatment have a domicile outside the UK have foreign income or capital gains and want to use the remittance basis for the 2025 to 2026 tax year
When you’re not a UK resident?
It can be helpful to first determine whether you qualify as a non-UK resident. You may need to file a non-resident tax return in the UK if any of the following apply:
- You were a resident in the UK for one or more of the previous three tax years, and you spent fewer than 16 days in the UK during the tax year.
- You were a resident for none of the previous three tax years and spent fewer than 46 days in the UK in the tax year.
- If you worked full-time overseas in the tax year and:
- spent less than 91 days in the UK
- worked no more than 31 days in the UK (a working day is 3 hours for this test)
- had no significant break in the overseas work (31 days or more) ## When are you a UK resident? You’re a UK resident for tax purposes if you spend 183 days or more in the UK in the tax year (which runs from 6 April to the following 5 April).
If you don’t meet this condition, then you may still be a resident if you own a home in the UK or work in the UK. You can find more information on these here.
What does the SA109 do?
The form does various things, including enabling people who are not UK residents to claim UK personal allowances and to allow those who are residents but not domiciled in this country (broadly people who are here for a limited period) to only pay tax on overseas earnings brought into the UK (the “remittance basis”).
Is this similar to the form R43?
If you are filling in a tax return, you are unlikely to also need form R43 (this is a form that enables you to claim personal allowances and a tax repayment if you're not resident in the UK). There is an overlap in what they do.
How do I submit the SA109?
You can’t submit the SA109 form directly through HMRC’s online self-assessment system. To fill out and submit the form online, you need to use approved tax software, like Taxd. Our software makes it easier and guides you through completing the SA109 and other related forms.
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.
Conclusion
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.
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 UK tax self-assessment process is complicated, but breaking it down step-by-step makes it much more manageable.
If you're struggling with the form, the Taxd online self-assessment platform allows you to submit your tax return to HMRC effortlessly.
FAQs
1. Do I need to file a non-resident tax UK return?
If you're non-resident, you do not pay UK tax on income or gains you get outside the UK. You may be non-resident the day after you leave the UK - this depends on your situation and how 'split year treatment' applies to you. You may need to pay non-resident tax if you don’t live in the UK but still have UK income.
2. What additional form is to be filled by non-UK residents?
You cannot use HMRC's online services to tell them about your income if you're not an on-resident. Instead, you must fill in a self-assessment tax return and an SA109 form and send them using Taxd.
3. Are non-residents liable for UK income tax?
Non-residents only pay tax on their UK income - they do not pay UK tax on their foreign income. Residents normally pay UK tax on all their income, whether it's from the UK or abroad.
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