US Tax Preparation for American Expats: Dual-Status Year

For most Americans moving to the United Kingdom there is no US dual-status year at all: US citizens are taxed on worldwide income for the full calendar year regardless of where they live. A genuine dual-status arrival or departure year arises only where US residency itself begins or ends — green card holders, visa holders, and expatriating individuals. Getting that distinction right is the foundation of every catch-up filing.

That single point is where most rebuilt arrival years go wrong, and why US tax preparation for american expats in the year of the move is the hardest return in any compliance catch-up. At Jungle Tax we rebuild these years constantly — usually because a previous preparer treated a US citizen’s departure as a dual-status year, or treated a green card holder’s genuine dual-status year as an ordinary full-year Form 1040. Both errors survive quietly for years, because the arrival year is rarely the year that triggers an IRS letter. It is the year that poisons the carryforwards.

What is a dual-status year, and does it apply when an American moves to the UK?

A dual-status year is a single tax year in which an individual is a US resident for part of the year and a US nonresident for the other part. The IRS is explicit that this concerns residency status, not citizenship or nationality. In a dual-status year, worldwide income is taxable for the resident portion, while only US-source income and income effectively connected with a US trade or business is taxable for the nonresident portion. The IRS sets out the mechanics in its guidance on the taxation of dual-status individuals and in Publication 519.

The critical consequence for our client base: a US citizen who relocates from New York to London does not have a dual-status year. Citizenship-based taxation means the return for the year of the move is an ordinary full-year Form 1040 reporting worldwide income from 1 January to 31 December, with relief delivered through the foreign earned income exclusion, foreign housing amounts, and the foreign tax credit — not through a residency split.

The genuine dual-status arrival or departure years in a US–UK context arise in a narrower and wealthier set of cases, which is precisely why they are so often mishandled by generalist preparers.

Which US–UK scenarios actually produce a dual-status year?

• The lawful permanent resident who leaves. A green card holder who formally abandons the card mid-year (or whose status is administratively or judicially terminated) has a residency termination date and a dual-status departure year. Simply moving to London and letting the card lapse in a drawer does not end residency — the card holder remains a US tax resident until abandonment is formalised or a treaty position is taken.
• The treaty tie-breaker year. A green card holder who becomes UK resident and claims non-resident status under the US–UK treaty residence article is treated as a nonresident for US income tax purposes from the tie-breaker date, disclosed on the treaty-based return position form. That produces a dual-status year in practice, while leaving the information-reporting obligations (FBAR, Form 8938, Forms 5471/8621) fully intact.
• The non-citizen spouse. A British spouse who has been a US tax resident under the substantial presence test and returns to the UK mid-year has a dual-status year. The American spouse in the same household does not. Two entirely different returns, same family, same removal van.
• The expatriating US citizen. A citizen who formally renounces mid-year is a citizen (and full-year taxpayer) up to the expatriation date and a nonresident afterwards — a dual-status year sitting alongside the exit-tax regime and the year-of-expatriation information return.
• The reverse move. An accidental American or long-term UK resident who takes a US assignment and first meets the substantial presence test has a dual-status arrival year in the US, with the mirror-image UK split year running in the opposite direction.

How is a dual-status return actually constructed?

A dual-status return is not two returns. It is one return with a controlling form and a supporting statement, and the ordering matters.

1. Fix the residency start or termination date. For an arrival, residency generally begins on the first day of physical presence in the year the substantial presence test is met, subject to the de minimis presence rules and any first-year election. For a departure, residency generally ends on the last day of physical presence, provided the individual establishes a closer connection to a foreign country for the remainder of the year and is not a US resident at any time in the following year. These dates are evidential, not aspirational: flight records, lease commencement, employment contract start, and UK arrival documentation all form part of the file.
2. Choose the controlling form by year-end status. Resident on 31 December means Form 1040 is the controlling return with the nonresident computation attached as a statement. Nonresident on 31 December — the usual outcome for someone leaving for the UK — means Form 1040-NR is the controlling return with the resident-period computation attached as the statement.
3. Label the package correctly. The IRS expects “Dual-Status Return” written across the top of the controlling form and “Dual-Status Statement” across the supporting one. A dual-status package generally cannot be e-filed. It goes on paper, which means the mailing evidence is the only proof of filing you will have.
4. Split the income by period, not by convenience. Worldwide income received while a resident; US-source and effectively connected income while a nonresident. Non-effectively-connected US-source passive income in the nonresident period is taxed at a flat 30% rate, or the reduced treaty rate, with no deductions permitted against it.
5. Apply the correct rate schedule and restrictions to the combined figure, which is where most of the value is lost.

Which reliefs disappear in a dual-status year?

This is the section generalist pages summarise in a sentence and get wrong. A dual-status year is a stripped-down year, and for a high-earning household the cost is material.

• No standard deduction. Itemised deductions only, and only those attributable to the correct period. For a household that has just paid UK stamp duty land tax and has no US mortgage interest, that can mean a near-zero deduction against a substantial resident-period income.
• No joint filing in the ordinary case. A dual-status individual generally cannot file a joint return, unless an election is made to be treated as a full-year US resident where the spouse is a US citizen or resident — an election that has consequences well beyond the year in question.
• No head of household status, and no corresponding tax tables.
• Restricted credits. The earned income credit and education credits are generally unavailable absent a full-year residency election. Refundable child tax credit interactions require careful modelling where the foreign earned income exclusion is also in play.
• A prorated foreign earned income exclusion, if any. The exclusion is limited by qualifying days: the annual maximum multiplied by qualifying days over days in the year. A move in September rarely produces meaningful exclusion in the year of arrival abroad, and the physical presence test may only be satisfied by a qualifying period spanning into the following year — which is why the arrival year so often needs an extension to a date beyond the ordinary deadline.
• No deduction or credit allocation shortcuts. Deductions and the foreign tax credit must be attributed to the period and the income they relate to. Blending them across the split is one of the most common errors we correct.

US and UK treatment of the year of the move, compared

Feature	United States (IRS)	United Kingdom (HMRC)
Tax year	Calendar year, 1 January to 31 December	6 April to 5 April
Does citizenship matter?	Yes — US citizens are taxed on worldwide income wherever resident	No — liability follows residence, not nationality
Is the year of the move split?	Only where residency starts or ends (dual-status). Never for a US citizen	Yes, if the individual is UK resident for the year and meets one of the statutory split-year cases
Residence test	Green card test or substantial presence test (weighted three-year day count)	Statutory Residence Test: automatic overseas tests, automatic UK tests, then sufficient ties
Relief for new arrivals	None equivalent; relief comes via exclusion and credit	Four-year foreign income and gains regime for qualifying new arrivals following a sufficient period of prior non-residence
Filing method in the split year	Paper filing; dual-status packages generally cannot be e-filed	Self Assessment return with the residence and remittance pages completed
Standard allowance	Standard deduction denied in a dual-status year	Personal allowance generally available to UK residents, subject to the high-income taper

How does UK split-year treatment interact with the US position?

The UK has its own, entirely separate concept of a split year. Split-year treatment applies only where the individual is UK resident for the whole tax year under the Statutory Residence Test and falls within one of the eight statutory cases — cases 4 to 8 cover arrivals, including starting to have a UK home, starting full-time work in the UK, and accompanying a partner. Where more than one case applies, statutory priority ordering determines which case governs and therefore the split date. HMRC’s consolidated guidance is the RDR3 Statutory Residence Test notes, and the residence manuals expand each case.

Three cross-border consequences follow, and none of them are handled by the US-only pages that dominate this search result:

• The split dates rarely agree. A UK split date of, say, 1 October sits inside a US calendar year that runs to 31 December. The overlap between the two systems for the year of the move is structural, not a rounding issue, and it must be reconciled explicitly on Form 1116 or the credit will be misstated.
• The four-year foreign income and gains regime can increase US tax. A qualifying new UK arrival who claims relief on foreign income and gains pays no UK tax on that income. For a US citizen, the same income remains fully taxable in the United States, and there is now no UK tax to credit against it. Relief on one side of the Atlantic can create a cash tax liability on the other — a modelling exercise that belongs in cross-border tax planning, not in a rushed return.
• Treaty relief has to be claimed consistently. The US–UK treaty allocates taxing rights on employment income, pensions, dividends and gains, and the saving clause preserves the US right to tax its citizens with specified exceptions. Positions taken in the arrival year set the pattern every subsequent year is measured against.

Why does the mismatched tax year break the foreign tax credit?

UK income tax on the arrival-year salary is largely collected through PAYE across a UK tax year that straddles two US calendar years. A US filer claiming the foreign tax credit must decide between the cash basis and the accrual basis, and that election is sticky: once made, the accrual basis generally binds all later years. Choosing it in the arrival year to solve a timing problem commits the taxpayer for the rest of their time abroad. Choosing the cash basis without modelling the effect can push credits into a year with no matching income, creating carryforwards that expire unused.

Add the basket rules — general category, passive category, and any treaty re-sourced amounts — and the arrival year is where every later Form 1116 gets its opening balances. Our US–UK tax accountants rebuild these baskets from source documents rather than rolling forward a prior preparer’s figures.

Why does a wrongly built arrival year distort every later year of a streamlined submission?

The Streamlined Filing Compliance Procedures require a defined package: delinquent or amended returns for the most recent years for which the due date has passed, foreign bank account reports for a longer look-back period, full payment of tax and interest, and a signed non-willfulness certification. The IRS sets out the framework on its streamlined filing compliance procedures page.

Here is the structural problem. The arrival year is frequently outside the streamlined return window — it happened five, eight, twelve years ago. But it is not outside the computation. It is the year that generates the opening balances the in-scope years depend on:

• The foreign earned income exclusion election itself. Once made, the election continues until revoked, and revocation triggers a multi-year bar on re-electing without consent. A streamlined package that silently switches between exclusion and credit across the in-scope years, because the arrival year was reconstructed without checking what was originally elected, is internally inconsistent on its face.
• Foreign tax credit carryovers. Unused credits generated in the arrival year carry forward. If the arrival year is rebuilt on the wrong basis, or on a dual-status footing that should never have applied, every carryforward schedule in the streamlined package is wrong — and those schedules are exactly what an examiner reconciles.
• Basis, cost and currency. The dollar cost basis of a UK property, a share portfolio, or an employer equity award is set at acquisition. Arrival-year errors in translation dates or in the treatment of pre-arrival accruals propagate into every later disposal.
• Passive foreign investment company positions. UK investment funds, unit trusts and ISAs are typically PFICs for US purposes. The arrival year is when the holding entered the US net, and when any mark-to-market or qualified electing fund election could have been made. An unmade election in the arrival year forces the punitive default regime in every later year.
• Capital loss and passive loss carryovers, and any US net operating loss brought into the move.
• The narrative in the certification. The non-willfulness statement must explain, in plain terms, what the taxpayer understood and when. “I moved in 2018 and did not realise I still had to file” is a coherent narrative. It stops being coherent if the accompanying returns show a sophisticated dual-status split that only a professional could have prepared. Consistency between the arrival-year facts and the certification is a credibility issue, not a technical one.

Our IRS streamlined filing specialists therefore rebuild the arrival year even when it is not a year being filed. It goes into the working papers as a reconstruction schedule, not into the envelope.

Rebuilding the arrival year: the sequence we follow

1. Establish status, not assumptions. Citizen, green card holder, or neither — and on what date each changed. Passport stamps, USCIS records, and formal abandonment documentation where relevant.
2. Run the day counts on both sides. The weighted US substantial presence calculation and the UK Statutory Residence Test for the same physical movements, using a single reconciled travel calendar.
3. Determine whether a dual-status year exists at all. For a US citizen leaving for the UK, the answer is almost always no, and the return is a full-year Form 1040.
4. Identify the UK split-year case and date, applying the statutory priority ordering, and record why that case was chosen.
5. Build the income map by source and period — US employment through the move date, UK employment after it, equity vesting straddling the move, rental income, dividends, and any trailing US-source items.
6. Test the exclusion and the credit against each other. Prorated exclusion versus full credit, modelled for the arrival year and the following two years, because the arrival-year choice binds them.
7. Fix the foreign tax credit basis election and document the reasoning.
8. Catalogue every foreign account and asset for the account report and the specified foreign financial asset return, including UK pensions, ISAs, and investment platforms opened on arrival. Our FBAR penalty calculator helps quantify the exposure before a route is chosen.
9. Identify PFIC holdings and any elections that were or should have been made, and price the default regime if none were.
10. Carry the resulting balances forward into the in-scope streamlined years, and reconcile them to the certification narrative before anything is signed.

What goes wrong most often?

• Treating a US citizen’s departure year as dual-status, halving reported income and creating an understatement that compounds.
• Treating a green card holder’s departure year as a full-year Form 1040 when residency genuinely terminated, overstating income and overpaying.
• Claiming the standard deduction on a dual-status return.
• Filing a joint return in a dual-status year without a valid election, or making the election without modelling its multi-year effect.
• Claiming a full-year foreign earned income exclusion for a partial qualifying period.
• Assuming UK split-year treatment applies automatically, when it must be claimed and evidenced on the Self Assessment residence pages.
• Ignoring UK pensions, ISAs and investment platforms opened immediately on arrival — the classic trigger for a later disclosure.
• E-filing a dual-status package, or filing it without retaining proof of posting.

Deadlines and the practical calendar

US filers abroad benefit from an automatic extension beyond the ordinary April deadline, with a further extension available on request, and in arrival years a special extension may be needed to complete a qualifying period for the exclusion. Interest, however, runs from the original due date regardless of extension. On the UK side, the Self Assessment cycle for the tax year ending 5 April runs to the following 31 January for online filing and payment, with payments on account potentially due. Two calendars, two payment rhythms, and one cash-flow plan — which is why we sequence US tax services and UK tax services in the same engagement rather than in two disconnected ones.

Working with Jungle Tax on the arrival year

Jungle Tax prepares US and UK returns for founders, executives, fund principals and internationally mobile families. We are a preparation and compliance practice: we build the return, evidence the position, and file it. For catch-up work, the arrival year is the first thing we reconstruct and the last thing we sign off, because everything downstream inherits it. Our high net worth engagements typically combine a rebuilt arrival year, a full streamlined package, and a reconciled schedule of carryforwards the client can hand to any future adviser without apology. Further reading sits in our guides library.

If you moved between the United States and the United Kingdom and have never been confident that the year of the move was prepared correctly — or you are assembling a streamlined submission and the older years do not reconcile — contact our cross-border team for a confidential consultation. We will tell you plainly whether a dual-status year exists, what the arrival year should have looked like, and what it will take to put the record straight before the IRS or HMRC raises the question first.