How the SA109 Form Works: A Complete Guide
The SA109 is a supplementary Self Assessment form used by individuals with non-resident, dual-resident, or other international tax circumstances.Who Needs an SA109?
The form is commonly used by non-UK residents, individuals claiming split-year treatment, and taxpayers seeking relief under a double taxation agreement.
Major Update for 2026/2027: The traditional "remittance basis" for non-domiciled individuals has been completely abolished. The SA109 has been radically overhauled and is now renamed the Residence and Foreign Income and Gains (FIG) Regime form.
What Information Is Included?
For the 2026/2027 tax year, the SA109 contains sections covering:
- Residency Status: Determining your tax residence using the Statutory Residence Test.
- Split-Year Claims: Allocating your tax liabilities when moving into or out of the UK mid-year.
- The FIG Regime: Qualifying new arrivals (who were non-resident for 10 consecutive years) use this section to claim a 4-year 100% tax holiday on foreign income and gains.
- Temporary Repatriation Facility (TRF): Former remittance basis users use this section to report older, unremitted offshore funds brought into the UK at a special flat tax rate of 12%.
Why Is It Important?
HMRC uses the information on the SA109 to determine how UK tax rules interact with your physical presence, overseas ties, and international tax treaties under the new residence-based system.
Word of Warning
Claiming relief under the new FIG regime means you will forfeit your UK Personal Allowance and your Capital Gains Tax Annual Exempt Amount for that tax year. Because the transition from the old non-dom system is highly complex, getting the boxes wrong on the SA109 can trigger immediate HMRC inquiries or incorrect tax calculations.
Consider professional advice if your residency position spans multiple countries or if you are managing transitional offshore assets.