The year you move: why one American return has to be written twice

Figures relate to tax year 2025-26 (UK) · 2025 (US)

You landed at Newark in July and started work in August. The first seven months of the year happened entirely in Britain, and America had almost no interest in them.

The last five months are a different matter. America taxes its residents on worldwide income, so from the day you arrived your whole financial life came into scope. That split is what a dual status year means, and it makes the return harder than either a full year in or a full year out.

Key takeaways

• The moving year splits into a non-resident part and a resident part.
• It usually happens in the year you arrive in America or the year you leave.
• You cannot take the standard deduction on a dual status return.
• Filing jointly with a spouse is generally unavailable as well.
• Two elections can turn the year into a full resident year instead.
• The full year route often costs less, despite pulling in more income.

What is a dual status year?

It is a tax year in which you were a non-resident for one part and a resident for the other. America applies different rules to each part and asks for a single return covering both.

During the non-resident part, only American source income counts. During the resident part, everything counts, wherever in the world it arose.

So the same salary can be outside the system in June and inside it in September. The date you crossed matters enormously.

Who ends up filing one?

Mostly people arriving on a work visa part way through a year. A split return follows naturally from meeting the residence test in the middle of a calendar year. Departures produce them too. Someone giving up a green card and leaving in May has a resident period and then a non-resident one.

Our guide to moving to the US covers the planning that should happen before the flight.

Do US citizens ever file one?

Very rarely. America taxes its citizens on worldwide income wherever they live, so moving house changes nothing about the filing basis. The exception is the year of expatriation. Someone who renounces mid-year has a citizen period and a non-resident period, which produces the same split.

That year also brings its own form and its own exit calculations, covered in our guide to renouncing US citizenship.

How the year splits

Residence generally starts on the first day you were physically present in America in the year you meet the presence test. For a green card, it starts on the first day you held the card while present.

Per IRS guidance, the presence test counts all your days this year, a third of last year's days and a sixth of the year before. Reaching 183 on that weighted count makes you resident.

Residence ends on your last day of presence when you leave, provided you keep a closer connection to another country for the remainder.

Which form goes on top?

It depends on where you stood at the end of the year. Resident on 31 December means the resident return goes on top, with the non-resident part attached as a statement.

Non-resident on 31 December flips the order. The non-resident return leads and the resident period becomes the attachment.

Both versions carry a label across the top saying which kind of return it is. Missing that label causes real processing delays.

What you lose on a dual status return

The standard deduction, first of all. A dual status filer must itemise deductions or claim nothing, which hurts anyone without mortgage interest or large charitable gifts.

Joint filing goes too, along with the head of household rate band. Several credits become unavailable, and the rest need care.

Those restrictions are the whole reason people look for an election instead. The arithmetic usually favours avoiding the split.

A worked example

The figures below are illustrative and use round numbers to show the mechanics.

Rachel, a British citizen, moved to Boston on 1 August 2025 with her husband and two children. She earned £55,000 in Britain before leaving and $90,000 in America afterwards.

On a dual status return she reports only the American salary, but she loses the standard deduction and cannot file jointly. Her effective rate climbs sharply as a result.

On a full year election she reports the British salary too, then claims a credit for the British tax she already paid. She keeps the joint rates and the larger deduction.

In her case the second route saved around $6,000. In other cases it does the opposite, which is why both get calculated.

Comparing the routes

The first year choice

This election lets you start residence earlier than the ordinary rules allow, where you were present for a qualifying stretch of days. It suits someone who arrived late in the year and wants the resident period extended.

It comes with conditions about presence in the following year, so it sometimes has to wait for an extension. That timing catches people out.

It does not by itself give you the standard deduction. On its own it produces a longer resident period inside the same dual status year.

Electing full year residence instead

A separate election lets a couple treat the non-resident spouse as resident for the entire year and file jointly. That single choice removes the split and restores the deduction.

The price is worldwide income for the whole year, including the months before arrival. Foreign tax credits usually soak up most of the extra charge.

The election also continues until you revoke it, and revoking has consequences. Treat it as a decision for several years, not just this one.

What about the UK side of the same year?

Britain runs its own residence test, and it does not care what America decided. You can easily be resident in both countries for overlapping parts of the same year. The statutory residence test does the work there. Our guide to the UK statutory residence test sets out the day counts and the ties.

Where both countries claim you at once, the treaty tie-breaker decides. That claim needs disclosing, which we cover in our guide to Form 8833.

Does Britain split the year too?

It can, under split year treatment. Britain divides the tax year into a resident part and a non-resident part where you meet one of several specific cases. But the British tax year ends on 5 April and the American one on 31 December. So the two split years never line up, and income can fall into different years on each side.

That mismatch makes foreign tax credits awkward. Claiming a credit for tax paid in a different year needs care and sometimes needs a carryback.

How to prepare the return

1. Fix the exact date residence started or ended, with travel records to support it.
2. Split every income source into the periods either side of that date.
3. Identify which pre-arrival income had an American source.
4. Work out the dual status result using itemised deductions only.
5. Calculate the full year election result with credits for foreign tax.
6. Compare the two figures, including the effect on future years.
7. Label the return correctly and attach the statement for the other period.

What about a mid year bonus or share vesting?

These cause more trouble than salary. A bonus paid in September for work done in March belongs partly to the non-resident period, and it needs apportioning. Share awards behave the same way. Vesting after arrival does not make the whole award American, because the vesting period usually straddles the move.

Payroll almost never gets this right. Expect to correct it on the return rather than relying on the year end statement.

What happens to your pension and investments?

Everything you own comes into view on the day residence starts. A British workplace pension, an investment account and a rental flat all become reportable from that moment. Funds cause the most trouble. British collective investments often fall under punitive American rules, and holding them into the resident period can cost more than the move saved.

Bank accounts matter too. Once residence starts, foreign account reporting applies for the rest of the year, and the thresholds look at the highest balance rather than the average one.

So review the portfolio before you fly. Selling a holding while still non-resident is usually simpler than untangling it afterwards.

Does state tax follow the same split?

Not reliably. States write their own residence rules and several of them ignore the federal treatment entirely. New arrivals often find the state counts them as part year residents on a different date. California and New York in particular apply their own tests.

City taxes add another layer in a few places. New York City charges its own resident tax, and the date it starts may differ again from the federal one.

Check the state position separately, because the federal answer settles nothing there. Our guide to US state tax for expats explains the traps.

What if you leave and give up a green card?

Then the departure year is a dual status year and the exit rules may apply as well. Long term residents face the same expatriation tests as citizens who renounce. Handing the card back at a consulate starts a separate process with its own form. Simply moving abroad and letting the card lapse does not end the tax obligation.

Our guide to moving back to the US covers the return leg for anyone repeating the journey.

When is the return actually due?

The ordinary April deadline applies, though an extension buys you until October. Anyone abroad on the due date usually gets an automatic extension to June as well. Moving years often need the longer window. The first year choice can depend on days spent in the following year, so the answer simply does not exist in April.

File the extension anyway. It costs nothing and it keeps the election open while the facts settle.

Mistakes and penalties we see in moving years

The first is using consumer software. Most packages cannot produce a dual status return at all, and they file a full resident one instead.

The second is guessing the start date. A week either way moves real income across the line, and travel records settle it in minutes.

The third is skipping the election comparison. People pick the route their employer mentioned rather than the cheaper one.

The fourth is forgetting foreign account reporting for the resident period. That obligation starts the day residence starts, not on 1 January.

How US UK Tax Accountants helps

We fix the residence dates from your travel records, split the income properly, and run the dual status figure against the election figure before recommending either. Then we prepare whichever return wins.

We also line the American year up against the British one, so the credits land where they should. Our US federal return service covers the filing itself.

If you moved this year, or you are moving next year, get in touch. Arrival dates are much easier to plan before the flight than after it.

Last reviewed 24 September 2026. This article is general information and not personal tax advice. Every situation turns on its own facts, so take advice on yours before acting.