31 Jan
Filing Deadline
The UK tax year runs 6 April to 5 April, the American one follows the calendar, and HMRC and the IRS never compare notes on your behalf. If your Self Assessment is prepared in isolation, foreign tax credits get claimed against the wrong year, income gets sourced inconsistently, and one of the two returns eventually has to be amended. We prepare the SA100 as one half of a pair.
The work starts with residence. The Statutory Residence Test decides whether the UK can tax your worldwide income at all, and in an arrival or departure year, split-year treatment can take months of income out of UK charge entirely. Get that determination wrong and every number that follows is wrong with it.
How we deliver this service.
A rigorous, phase-driven process ensures nothing is missed and every position is defensible.
Residence Determination
We apply the Statutory Residence Test: the automatic overseas tests, the automatic UK tests, and the sufficient ties test, with day counts documented.
Split-Year Review
In arrival and departure years we test each of the eight split-year cases so that income earned before you became UK resident stays out of UK charge.
FIG Regime Assessment
For arrivals after 6 April 2025 we assess eligibility for the four-year foreign income and gains regime, which replaced the remittance basis.
Income & Property Pages
We prepare employment, self-employment, dividend, interest, capital gains, and UK property pages, including finance cost restrictions for landlords.
US Coordination
We reconcile the UK return against the US Form 1040 so foreign tax credits land in the right country, in the right year, at the right amounts.
Filing & Payments
We file online by 31 January, calculate both payments on account, and tell you exactly what to pay HMRC and when.
Residence Testing
Day counts and ties decide everything.
Since 2013 UK residence has been mechanical, not impressionistic. The Statutory Residence Test works through automatic overseas tests, automatic UK tests, and then a sufficient ties test that weighs family, accommodation, work, and past presence against your days in the UK. A person with three UK ties can become resident at just 46 days; someone with none can stay non-resident up to 182.
In the year you move, split-year treatment matters even more. If you qualify under one of the eight cases, the tax year divides into a UK part and an overseas part, and foreign income earned in the overseas part never enters the UK return. We document the case you qualify under, because HMRC can ask, and because the US return needs to tell the same story.
Residence focus: SRT day counting, sufficient ties analysis, split-year Cases 1 to 8, and departure planning for those leaving the UK.
Tailored for every client profile.
New Arrival Planning
The rules for new arrivals changed in 2025.
For decades, non-domiciled residents could elect the remittance basis and keep foreign income and gains outside UK tax as long as the money stayed offshore. That regime closed on 5 April 2025. From 6 April 2025, the replacement is the foreign income and gains regime: a claim available for your first four years of UK residence, provided you were non-resident for the ten years before arriving.
The FIG regime is simpler but less forgiving. Claim it and your foreign income and gains escape UK tax for those four years, with no need to keep the money offshore, but you give up your personal allowance and capital gains annual exempt amount. Anyone with pre-2025 remittance basis history also needs their old unremitted income tracked, because bringing it to the UK can still trigger tax. We model whether the claim pays for itself each year.
FIG focus: four-year FIG claims, Temporary Repatriation Facility for old unremitted income, and the interaction with US worldwide taxation.
HMRC Compliance
Two payment dates, one filing date, no surprises.
Paper returns are due 31 October; online returns and the balancing payment are due 31 January after the tax year ends. If your last bill was over 1,000 pounds and less than 80% of your tax was collected at source, HMRC also wants payments on account: half your prior-year liability on 31 January and half on 31 July. Miss these and interest starts running immediately, with penalties layering on top.
We also deal with HMRC for you. That includes registering you for Self Assessment, responding to enquiry letters, applying for an NT code so a UK employer or pension stops withholding PAYE when a treaty says the income is not taxable in the UK, and chasing refunds when too much was collected. You should not have to sit on hold with HMRC from another time zone.
Compliance focus: 31 January and 31 October deadlines, payments on account, NT code applications, and HMRC enquiry handling.
Facing your first Self Assessment?
Residence, split-year treatment, and the FIG regime are decided in your first UK return. Talk to us before 31 January, not after.
Specific deliverables, precisely documented.
“HMRC and the IRS each want their own return, on their own year, under their own rules. We prepare yours so the two tell the same story and tax the same pound once.”
Technical clarifications.
Answers to the most frequently asked questions about how this service works in practice.
Online returns are due 31 January following the end of the tax year on 5 April, and any balancing payment is due the same day. Paper returns are due earlier, on 31 October. If you have never filed before, you must register for Self Assessment by 5 October after the tax year ends.
They are advance payments toward next year's bill, each equal to half of this year's liability, due 31 January and 31 July. HMRC requires them when your last bill exceeded 1,000 pounds and less than 80% of your tax was collected at source. If your income has dropped, we can apply to reduce them.
Not for 2025/26 onward. The remittance basis was abolished from 6 April 2025 and replaced by the FIG regime, which exempts foreign income and gains for your first four years of UK residence if you were non-resident for the prior ten. Income kept offshore under old remittance basis claims is still taxable if remitted, so the history has to be tracked.
As a US citizen or green card holder you file in both countries, and UK tax paid becomes a foreign tax credit on the US return. Because the tax years do not align, the credit has to be matched to the right US year. We prepare or coordinate both returns so the figures agree and nothing is credited twice or missed.
Related services.
Two Tax Systems, One Team
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