SA109
HMRC, Residence, Remittance Basis etc.
The Self Assessment pages for residence status, split-year treatment, treaty residence claims and foreign income and gains claims.
What is SA109?
SA109 is where a UK return states the taxpayer's residence position and makes the claims that depend on it. It still carries its old name, but the remittance basis was abolished from 6 April 2025. The pages now matter most to people arriving in or leaving the UK, and to anyone resident in both countries.
Stating your residence position to HMRC
UK residence is decided by the Statutory Residence Test, which combines automatic overseas tests, automatic UK tests and a sufficient ties test.
It is not a simple day count, and it works differently from the US substantial presence test. SA109 records the outcome for the year and, where relevant, the facts behind it. A person can be UK resident under the SRT while also being a US resident or citizen.
Split-year treatment divides a year of arrival or departure into a UK part and an overseas part when one of the statutory cases applies. It is claimed on SA109, and it affects which income the UK taxes. Treaty residence claims also go here: a person resident in both countries under their domestic rules can rely on the treaty's tie-breaker to be treated as resident in one of them for treaty purposes.
From 6 April 2025, new arrivals who were not UK resident in any of the previous ten tax years can claim the foreign income and gains regime for up to four tax years. Foreign income and gains covered by a valid claim are not taxed in the UK, but claiming has costs, including the loss of the personal allowance for that year. SA109 cannot be filed through HMRC's free online service, so commercial software or a paper return is needed.
At a glance
- The SA100 Self Assessment return
- Attached to
- The Statutory Residence Test, not a day count alone
- Residence test
- Up to four tax years for qualifying new arrivals
- FIG regime
- Commercial software or paper, not HMRC's free service
- Filing route
Figures are for the tax year stated in the official instructions linked below.
How we handle it
- UK Self Assessment
Self Assessment returns for UK residents with US income, residence questions or treaty claims, prepared with the US return in view.
- Treaty Relief
Claims under the US/UK income tax treaty, with Form 8833 disclosure, residence tie-breaker analysis and reduced withholding on US income.
- Cross-Border Tax
US and UK returns prepared together from one set of workpapers, so credits, tax years and exchange rates line up across both.
- Tax Planning
Forward planning across the US and UK tax systems: timing income, choosing investments, arriving, leaving and organising family finances.
Where people go wrong
The SA109 errors we correct most often.
Who files it
- People arriving in or leaving the UK during the tax year
- New UK residents claiming the foreign income and gains regime
- People resident in both the UK and US claiming treaty residence
- Non-residents filing a UK return for UK-source income
01
Assuming a low UK day count alone settles non-residence
02
Claiming split-year treatment without checking which statutory case applies
03
Describing the remittance basis as still available after April 2025
04
Making a FIG claim without costing the lost allowances first
Why US UK Tax Returns
Every form is prepared against the official instructions, and every position on it is one we can point to in the Code, the treaty or HMRC's guidance.
One File
US and UK returns prepared in the same engagement and reconciled line by line.
Primary Sources
Every position traced to the Code, the treaty, IRS instructions or HMRC guidance.
Scope First
Returns, forms, years and fee agreed in writing before work begins.
The Same People
The team that files this year carries the elections and credits into the next.
Questions we are asked
I moved to London from New York in September. Am I taxed in the UK on the whole year?
Not necessarily. If one of the split-year cases applies, the year is divided and the UK generally taxes foreign income only from the arrival date. The claim is made on SA109. You may also qualify for the foreign income and gains regime if you had not been UK resident in the previous ten tax years. Which applies depends on the facts of the move.
I used to claim the remittance basis. What replaced it?
The remittance basis was abolished from 6 April 2025. It was replaced by the foreign income and gains regime, which is available for up to four tax years to people who had not been UK resident in the previous ten tax years. People who were long-standing remittance basis users may not qualify and may instead be taxed on the arising basis, with transitional reliefs to review.
How do I claim to be treaty resident in the US rather than the UK?
The treaty tie-breaker applies only when someone is resident in both countries under each country's own rules. It looks in turn at permanent home, centre of vital interests, habitual abode and nationality. The claim is made on SA109 and, on the US side, disclosed on Form 8833 where required. Treaty residence changes which country has primary taxing rights, not whether returns are needed.
Primary sources
What this page says is drawn from the official material below. Read it yourself; we would rather be checked than trusted.
Last reviewed
Also in UK Forms
From the Blog
Need SA109 prepared or reviewed?
Tell us where you live, what you hold and which years are outstanding. We will say what applies and what it involves before any work begins.
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