Introduction
A dual-status year splits a single tax year into a resident period and a non-resident period, taxing each under entirely different rules, and it catches wealthy transatlantic families at precisely the moment their affairs are most complicated. Furthermore, it arrives in the year you gain or lose US resident status, which is exactly when a relocation, a green card surrender or a renunciation is already consuming your attention. The filing that results looks nothing like an ordinary return.
At TaxYork, we prepare US and UK returns for investment bankers, fund principals, company owners and their families moving between London and the United States. Consequently, we handle these transition years constantly, and we see the same expensive misunderstanding again and again. Clients assume that moving countries simply changes where they file. In reality, it can change how the entire year is taxed, which deductions vanish, and which elections must be made by a hard deadline.
This guide explains who genuinely faces a dual-status year and, importantly, who does not. Additionally, it sets out the forms, the lost standard deduction, the elections that can rescue the position, and the exit tax that ambushes long-term green card holders. Above all, it shows why the decisions you make in this one year echo for a decade.
What a Dual-Status Year Actually Means
A dual-status year is a single tax year in which you are a US resident for part of the year and a non-resident for the remainder. Furthermore, each period is taxed under its own regime, and you cannot simply blend them. The IRS sets out the framework in its guidance on the taxation of dual-status individuals.
Who Faces a Dual-Status Year
The people most exposed are green card holders and other US resident aliens who move between the United Kingdom and the United States. Specifically, the year you arrive and become a US resident, and the year you leave and abandon residence, both typically produce dual-status treatment. The IRS explains the residency rules in Publication 519.
Timing drives everything here. Accordingly, someone surrendering a green card in June faces a very different return from someone surrendering it in December, because the split point moves with the date residency ends.
Who Does Not Face One
This distinction matters enormously, and misunderstanding it costs real money. A US citizen living in the United Kingdom does not have a dual-status year merely for moving. Rather, citizenship-based taxation means a citizen remains a full-year US resident for tax purposes wherever they live, filing a complete Form 1040 every single year.
Therefore, an American who relocates from New York to London stays a full-year filer throughout. The only moment a citizen enters dual-status territory is the year they formally renounce citizenship, which is an expatriation event with its own severe consequences discussed below.
How the Two Periods Are Taxed
During your resident period, the United States taxes your worldwide income from every source. Conversely, during your non-resident period, it taxes only income effectively connected to the United States or arising from US sources. Consequently, the same salary can be fully taxable in one half of the year and entirely outside the US net in the other.
The Forms and the December 31 Rule
Preparing a dual-status return is a two-form exercise, and which form leads depends entirely on one date. Furthermore, getting the lead form wrong invalidates the return.
Which Form Leads Depends on Your Year-End Status
Your status on 31 December determines the primary return. Specifically, if you are a US resident on the last day of the year, you file Form 1040 as your main return with a dual-status statement attached. If you are a non-resident on that day, you file Form 1040-NR as the main return with a Form 1040 attached as a supporting statement.
You must also mark the return clearly. Accordingly, you write "Dual-Status Return" across the top and "Dual-Status Statement" across the attachment, so the IRS processes it correctly rather than rejecting it as inconsistent.
The Departure Year Leaving the UK for the US
Someone arriving in the United States from London mid-year usually ends the year as a resident. Therefore, Form 1040 leads, capturing worldwide income from the arrival date onward, while the pre-arrival period reports only US-source income. The substantial presence test generally sets the date residency begins.
The Departure Year Leaving the US for the UK
The mirror image applies when a resident alien leaves the United States for the United Kingdom and abandons their green card. Consequently, they usually end the year as a non-resident, so Form 1040-NR leads. Worldwide income is taxed only up to the residency termination date, and US-source income alone is taxed thereafter.
The Deductions and Credits You Lose
A dual-status year strips away reliefs that ordinary filers take for granted. Furthermore, these losses frequently outweigh any benefit from carving the year in two.
No Standard Deduction
Dual-status taxpayers cannot claim the standard deduction at all. Instead, you must itemise, which for a client with few itemisable expenses removes a substantial slice of tax-free income. The IRS confirms the restriction in Topic no. 551.
This single rule surprises clients more than any other. Notably, a high earner mid-move often has minimal mortgage interest or charitable giving to itemise, so the lost deduction translates directly into additional tax. Neutral background on the standard deduction appears at Investopedia's explainer.
No Joint Return and Restricted Credits
You generally cannot file a joint return for a dual-status year. Additionally, several credits are limited or unavailable, and you cannot use the head of household rates. For married couples relocating together, losing joint filing can push income into higher brackets precisely when relocation costs are highest.
The Foreign Earned Income Exclusion Still Applies Carefully
The foreign earned income exclusion remains available for the qualifying portion of the year, but it must be prorated to the days you genuinely lived abroad. Consequently, families with children should weigh it against the foreign tax credit, because claiming the exclusion forfeits the refundable Additional Child Tax Credit. We examine that trade-off within our US tax returns for expats service every filing season.
The Elections That Can Rescue the Position
The tax code offers several elections that can convert a punishing dual-status year into a full-year resident return. Furthermore, the right election frequently saves more than any other single decision in the transition.
The First-Year Choice
A non-resident who becomes a US resident under the substantial presence test in the following year may elect first-year choice to be treated as a resident for part of the arrival year. Consequently, this can accelerate residency and, combined with a spousal election, open the door to a full-year joint return. The IRS details the mechanics in its guidance on US tax residency and the first-year choice.
The Section 6013(g) and 6013(h) Elections
Where one spouse is a US citizen or resident, the couple may elect to treat the non-resident spouse as a resident for the entire year. Therefore, the dual-status restrictions fall away, the standard deduction returns, and joint filing becomes available. However, the election subjects the electing spouse to US tax on worldwide income, so we model it carefully before recommending it.
Weighing the Election Against Worldwide Exposure
An election that restores the standard deduction also exposes a full year of foreign income to US tax. Accordingly, the decision turns on the size and character of that income, the UK tax already paid, and the availability of credits. For a client with substantial UK investment income, electing full-year residency can cost more than the dual-status restrictions it removes.
Expatriation: When Citizens Enter Dual-Status Territory
The one route by which a US citizen reaches a dual-status year is renunciation. Furthermore, this path carries the heaviest consequences of all, because it can trigger the exit tax.
The Year of Renunciation
In the year you formally renounce US citizenship, you are a citizen for part of the year and a non-citizen thereafter. Consequently, you file a dual-status return, typically Form 1040-NR with a Form 1040 attached covering the period before expatriation. The expatriation tax provisions govern the treatment.
The Exit Tax and Covered Expatriates
Long-term green card holders and citizens who meet the net worth or tax liability thresholds become covered expatriates. Therefore, they face a mark-to-market exit tax that treats worldwide assets as sold the day before expatriation. For wealthy clients with appreciated portfolios, this deemed disposal can crystallise a very large gain in a single year. Professional commentary on the expatriation regime is published by the American Institute of CPAs.
Form 8854 and the Final Return
Covered expatriates must file Form 8854 with the final return and mail a signed copy separately. Additionally, missing this form causes a taxpayer to remain treated as a US person for tax purposes, defeating the entire point of expatriating. We coordinate this filing through our cross-border planning service, because the sequencing must be exact.
A Worked Example From Our London Practice
The following illustrative case reflects scenarios we handle regularly. All figures are rounded and use an exchange rate of $1.30 to the pound.
The Client's Position
A British-American couple relocated from London to New York in July, where the US-citizen spouse took a senior banking role. The other spouse held a UK passport only and had never been a US resident. Before the move, the family earned UK employment income and held a substantial UK share portfolio producing dividends and gains.
The citizen spouse remained a full-year US filer throughout, because citizenship never lapses. Meanwhile, the non-citizen spouse became a US resident on the July arrival date and therefore faced a classic dual-status year, with UK-source income before July and worldwide income afterwards.
The Election Decision
Filed separately as a dual-status taxpayer, the arriving spouse lost the standard deduction and paid tax on roughly $140,000 of post-arrival income without it. However, the couple could elect under section 6013(g) to treat the arriving spouse as a full-year resident and file jointly.
That election restored the joint standard deduction of about $30,000 and lower joint brackets. Nevertheless, it also exposed the arriving spouse's pre-arrival UK income of approximately $95,000 to US tax. Because UK tax on that income had been roughly £28,000, or $36,400, the foreign tax credit fully sheltered it.
The Outcome
The election saved approximately $9,100 in the transition year through the restored deduction and joint brackets, while the credit neutralised the additional worldwide exposure entirely. Consequently, the couple filed jointly, claimed the full credit, and carried forward surplus credit of around $4,000. Above all, modelling both routes before the deadline turned a costly default into a planned outcome.
How TaxYork Can Help
We provide comprehensive US personal tax services and US UK tax returns preparation for high-net-worth individuals, investors and company owners moving between the United Kingdom and the United States. Furthermore, we treat the transition year as a planning opportunity rather than a mechanical filing exercise.
Our work covers dual-status return preparation, the first-year and spousal elections, foreign tax credit optimisation through our tax treaty optimisation service, and expatriation planning including the exit tax and Form 8854. Additionally, we address missed reporting on UK pensions, investment accounts and foreign holdings through our FBAR and FATCA reporting and IRS Streamlined Filing services, because a relocation frequently surfaces older compliance gaps. Guidance on the UK side appears at GOV.UK's pages on tax when moving abroad and through HM Revenue and Customs.
Clients typically come to us mid-move, already stretched. Consequently, our first task is to fix the deadlines that cannot be missed and model the elections while they remain available.
Conclusion
A dual-status year divides one tax year into resident and non-resident periods taxed under different rules, and it strips away the standard deduction, joint filing and several credits. Furthermore, it affects green card holders entering or leaving the United Kingdom, and citizens only in the year they renounce. For covered expatriates, the exit tax can crystallise a decade of gains in a single filing.
The elections available can transform the outcome, but they carry hard deadlines and worldwide consequences that demand modelling. Therefore, anyone gaining or losing US resident status across the Atlantic should plan the transition year in advance rather than reconstruct it afterwards. The cost of drifting into the default treatment is rarely small.
Contact Us
If you are moving between the United Kingdom and the United States, surrendering a green card, or considering renunciation, we should plan your transition year before the deadlines close. Please book a consultation with our team, or contact us to discuss your position confidentially.
Email hello@taxyork.com or telephone 020 3488 8606. Additionally, we welcome enquiries from taxpayers with missed US tax returns, missed FBAR filings or unreported UK pensions and investment accounts.
Disclaimer
This article provides general information about US and UK tax rules current at July 2026 and does not constitute tax advice for any individual or entity. Tax legislation, rates, thresholds and exchange rates change, and the figures in the illustrative example are rounded and simplified. Consequently, you should obtain professional advice tailored to your circumstances before acting. TaxYork accepts no liability for any action taken or omitted in reliance on this content.