Introduction: Form 1040-NR and the British Spouse Question
Form 1040-NR is the return the United States uses to tax people who are not American. Consequently, it is the form that decides whether your British husband or wife owes anything at all. Most cross-border couples in London ask the question the wrong way round. They ask whether the British spouse should be added to the American spouse's return. In reality, the prior question matters far more.
That question is simple. Does your British spouse have income the United States is entitled to tax? If the answer is no, they file nothing. If the answer is yes, they file their own return, separately, in their own name.
At TaxYork we act for many couples in exactly this position. One spouse is American, or holds a green card. The other is British, has never lived in the United States, and has no intention of moving there. Nevertheless, the British spouse frequently owns something American. A Boston flat. A holding of US shares. Occasionally, days worked in New York for a US employer.
Furthermore, the stakes are higher than most couples expect. Get the treatment right and a British spouse pays modest tax on a net figure. Get it wrong and the Internal Revenue Service taxes the same income at 30% of gross, with no deductions whatsoever. This guide sets out precisely where that line falls.
Form 1040-NR Is a Different Return, Not a Variant of Form 1040
Begin with the architecture. Form 1040 taxes US citizens and residents on worldwide income. By contrast, Form 1040-NR taxes a nonresident on US-source income only. Therefore the two returns start from entirely different premises.
That distinction protects your British spouse. Their salary from a London employer is invisible to the IRS. So is their ISA, their SIPP, their UK rental property and their share of the family home. Additionally, none of it appears anywhere on Form 1040-NR. The United States simply has no claim to it.
However, the same architecture removes reliefs an American takes for granted. A nonresident gets no standard deduction. They cannot file a joint return. Moreover, they cannot use head of household rates. Those restrictions appear plainly in the IRS instructions for Form 1040-NR.
Why Most British Spouses File Nothing At All
Here is the reassuring part, and it applies to the majority of couples we advise. A British spouse who lives in Britain, works in Britain and invests in Britain has no US filing duty. They do not sign the American spouse's return. Equally, they do not need a US tax number.
Consequently, the American spouse simply files as married filing separately. Where the British spouse has no US tax number, the IRS instructions direct the American to enter "NRA" in the space for the spouse's identifying number. That single entry resolves the position for a great many households.
The Three Questions That Decide Everything
Every case we review turns on three questions. Firstly, is the British spouse a US tax resident under the day-count rules? Secondly, do they hold income from a US source? Thirdly, has US tax already been withheld at the correct rate?
Answer those three and the Form 1040-NR position follows automatically. The rest of this guide works through each in turn. Notably, a Form 1040-NR is never filed jointly with an American spouse. Above all, remember that residency is tested by presence and by immigration status, never by marriage. Marrying an American does not make anyone a US taxpayer, a point the IRS guidance on nonresident aliens makes clear.
When Your British Spouse Must File Form 1040-NR
The filing triggers are narrower than most guides suggest, but one of them is much wider than couples expect. Accordingly, it pays to read the conditions precisely rather than relying on intuition.
Trigger One: Engaged in a US Trade or Business
The first trigger catches anyone engaged in a US trade or business during the year. Critically, the IRS states that you must file even if you had no income from that business. You must also file where you had no US-source income at all. Remarkably, you must file even where a treaty exempts the income entirely.
That is a genuine trap. A British spouse who is a partner in a US partnership files Form 1040-NR regardless of profit, and the IRS guidance on taxing nonresident aliens confirms the point. The same applies to a spouse running a consultancy with American clients on US soil. Therefore a loss-making year still creates the obligation.
Trigger Two: US-Source Income Not Satisfied by Withholding
The second trigger is the common one. Your British spouse holds US-source income, and the tax withheld at source does not settle the liability. Rental income from an American property is the classic example, because nobody withholds correctly on it.
Additionally, income effectively connected with a US business always requires a Form 1040-NR. Meanwhile, passive income such as dividends may be fully settled by withholding at source. Consequently, the answer depends entirely on which bucket the income falls into.
Trigger Three: Claiming a Refund or a Treaty Position
The third trigger is voluntary, and it is where money is usually recovered. Suppose a US broker withheld 30% on your British spouse's dividends. The US-UK treaty caps that at 15%. Therefore filing Form 1040-NR is how you reclaim the difference.
Similarly, a treaty position that reduces or eliminates US tax generally requires disclosure on Form 8833. Furthermore, a refund claim carries its own deadline, generally three years from the due date of the return. Consequently, delay costs real money, because the oldest year drops away each April.
When Filing Nothing Is the Correct Answer
Sometimes the right advice is to do nothing, and a good adviser says so. Where a British spouse's only US income is portfolio dividends already withheld at the correct treaty rate, no return is required. The withholding is final. Likewise, most US bank deposit interest paid to a nonresident escapes US tax altogether.
Nevertheless, we still recommend documenting the analysis and the conclusion that no Form 1040-NR was due. Should the position later change, that file becomes the evidence that the earlier years were handled correctly.
What Counts as US-Source Income for a British Spouse
Sourcing decides everything, yet most couples have never seen the rules written down. Furthermore, the surprises run in both directions. Some income your spouse assumes is American is not. Some income they assume is safe is fully taxable.
Days Worked on American Soil
Employment income is sourced where the work is physically performed. Therefore a London banker who spends fifteen days a year in the New York office has US-source wages for those fifteen days. That is true even where the employer is British and the salary never touches an American bank.
However, the treaty usually rescues the position. Article 14 exempts the remuneration from US tax where three conditions are all met. Firstly, the spouse spends no more than 183 days in the United States in any twelve-month period beginning or ending in the year. Secondly, the employer is not a US resident. Thirdly, the pay is not borne by a US permanent establishment of that employer.
Consequently, a typical London employee on short business trips owes nothing and files no Form 1040-NR. Nevertheless, the exemption fails the moment a US entity recharges the cost, which happens routinely inside international groups. Therefore check the recharge before assuming the exemption applies.
US Real Property
Real property income is sourced where the land sits, without exception. Therefore rent from a Boston flat is US-source income however the money is paid or received. Additionally, gains on selling that property are US-source and taxable, which Article 13 of the treaty expressly confirms. Therefore a disposal always reaches Form 1040-NR.
Dividends and Interest From American Payers
Dividends paid by a US corporation are US-source, and so is interest paid by most US obligors. Consequently, a British spouse holding American shares in a UK brokerage account still has US-source dividends. The location of the account is irrelevant. The residence of the payer decides it.
Nevertheless, two large exceptions matter. Portfolio interest on most modern US debt instruments is exempt from US tax under domestic law. Similarly, interest on ordinary US bank deposits paid to a nonresident is generally exempt. Therefore many British spouses find their interest income carries no US charge at all, and no Form 1040-NR follows from it.
The Capital Gains Exemption Almost Nobody Mentions
Here is the point that surprises clients most, and it is worth real money. A British spouse who sells US shares at a profit generally pays no US tax on the gain. Article 13 of the treaty provides that gains on property other than real property "shall be taxable only in the Contracting State of which the alienator is a resident".
Consequently, a UK-resident spouse selling a large holding of American technology stock reports the gain to HMRC alone. The United States takes nothing. Domestic US law does contain a backstop charging nonresidents on capital gains where they are present in the country for 183 days or more, but a genuine UK resident never reaches that threshold.
One caveat deserves flagging. Article 13 permits the other state to tax gains where the individual was resident there at any time in the six years before the sale. Therefore a spouse who previously lived in America should take advice before selling, because a Form 1040-NR may still be required.
The Two Income Buckets and What the Treaty Does to Each
Everything on Form 1040-NR flows from a single split. The United States divides a nonresident's income into two buckets and taxes them on completely different principles. Understanding the split is the whole game.
Effectively Connected Income: Net, at Graduated Rates
The first bucket is income effectively connected with a US trade or business. This income is taxed much as an American would be taxed. Specifically, your British spouse deducts allowable expenses and pays graduated rates on the net figure.
Consequently, effectively connected income is the favourable bucket. A US rental property producing £40,000 of rent and £33,000 of costs is taxed on the £7,000 margin. Therefore the mortgage interest, the property taxes, the management fees and the depreciation all count on the Form 1040-NR computation.
Fixed, Determinable, Annual or Periodical Income: 30% of Gross
The second bucket is everything else, known as FDAP income. It covers dividends, interest, rents, royalties and similar passive receipts. Here the mechanism changes completely. The United States charges a flat 30% on the gross amount, and it allows no deductions at all.
That is the sentence that costs British spouses the most money. Thirty per cent of gross rent, with no relief for the mortgage, frequently exceeds the entire economic profit. On Form 1040-NR, this bucket is reported on Schedule NEC rather than in the main body of the return.
The Treaty Rates a British Spouse Can Actually Claim
Now the good news, and it is genuinely valuable. The US-UK income tax treaty overrides that 30% default for several categories. We verified each rate against the treaty text itself.
Article 10 caps US tax on portfolio dividends at 15% of the gross amount. Article 11 goes further, providing that interest arising in one state and beneficially owned by a resident of the other "shall be taxable only in that other State". Therefore US-source interest is generally free of US tax for a UK resident. Article 12 applies the same rule to royalties.
Consequently, a British spouse with US dividends and US bond interest should suffer 15% and nil respectively. Anything more has been over-withheld, and only a Form 1040-NR recovers it. Our tax treaty optimisation work exists largely to recover exactly these amounts.
Fixing the Problem at Source With Form W-8BEN
Prevention beats recovery, and one short form does most of the work. By giving the US payer a valid Form W-8BEN, your British spouse certifies UK residence and claims the treaty rate before payment. Consequently, the broker withholds 15% on dividends rather than 30%.
Additionally, the payer then reports the income on Form 1042-S rather than leaving it unreported. We cover the reconciliation in our guide to Form 1042-S and US-source withholding. Importantly, a W-8BEN expires at the end of the third calendar year after signature, so it must be refreshed. Otherwise the 30% rate returns and a Form 1040-NR becomes necessary again.
US Property and the Section 871(d) Election That Changes Everything
If your British spouse owns American property, this single election is worth more than every other point in this article combined. Furthermore, it is routinely missed by advisers who do not work in this niche.
The Default Position Is Punitive
Without the election, US rental income is FDAP income. Consequently, the IRS charges 30% of the gross rent. Your spouse deducts nothing. The mortgage interest does not count. The property taxes do not count. Depreciation does not count either.
Consider the arithmetic on a $54,000 rent roll. The default charge is $16,200. Meanwhile, the property might generate only $10,000 of genuine profit after costs. Therefore the tax exceeds the profit by a wide margin, and the investment loses money purely through the filing treatment.
Many advisers assume the treaty solves this, and they are wrong. Article 6 deals with income from real property and confirms that such income "may be taxed" where the property sits. Importantly, it stops there. Unlike several other US treaties, the US-UK treaty contains no net-basis election for real property income. Therefore the treaty gives no escape from the 30% gross charge, and Form 1040-NR must carry a domestic election instead.
How the Election Works
Section 871(d) allows a nonresident to elect to treat income from US real property as effectively connected with a US trade or business. The effect is immediate. Consequently, the income moves from the 30% gross bucket into the net, graduated bucket.
On the same $54,000 example, tax falls from $16,200 to roughly $1,000 on the $10,000 net. That is not a marginal saving. Rather, it is the difference between a viable investment and a loss-making one, and it turns on a single box on Form 1040-NR.
Making the Election Correctly, and Living With It
The election is made on Form 1040-NR itself, at Item M of Schedule OI. Your spouse ticks the box confirming the first year of the election. Additionally, the return must carry a statement listing the property, the nature and location of the interest, any substantial improvements, the income, and the dates of ownership.
Critically, the election applies to all income from all US real property held for the production of income. Therefore it is not a property-by-property choice. Moreover, once made, the election remains in effect for all future years until revoked with the consent of the Commissioner. Treat it as a one-way door.
Selling the Property Later
Disposal brings a separate regime. When a nonresident sells US real estate, the buyer must generally withhold a percentage of the gross sale price under the FIRPTA rules, reported on Form 8288. That withholding is a payment on account, not a final tax.
Consequently, your British spouse recovers any excess by filing Form 1040-NR for the year of sale. We have written separately on FIRPTA withholding when selling US property from abroad. Nevertheless, the point to hold onto is simple. The sale always creates a filing obligation, even where the property produced losses throughout.
The Section 874 Trap: Filing Late Destroys the Deductions
This provision turns a modest problem into a severe one, and almost no competing guide covers it. Accordingly, we treat it as the most important compliance deadline on Form 1040-NR.
What the Statute Says
Section 874(a) is unambiguous. A nonresident alien individual "shall receive the benefit of the deductions and credits allowed to him in this subtitle only by filing or causing to be filed with the Secretary a true and accurate return".
Read that carefully. Deductions are not an entitlement for a nonresident. Instead, they are conditional on filing. Therefore a British spouse who never files a Form 1040-NR does not simply owe tax late. They lose the right to deduct anything at all. The codified text of section 874 admits no exception for innocent ignorance.
The Sixteen-Month Rule
The regulations under section 874 then attach a deadline. Where a return was filed for the preceding year, or this is the first required return, the return must generally be filed within 16 months of its due date. Where no return was filed for the preceding year, the period ends earlier still. Specifically, it ends on the earlier of that 16-month date or the date the IRS mails a notice about the unfiled return.
Miss it, and the consequence is severe. The IRS then assesses tax on gross income, without allowance for deductions or credits. Consequently, our $54,000 rental example reverts to a charge on the full $54,000, even where the section 871(d) election would otherwise have applied.
The Waiver, and Why You Should Not Rely On It
A waiver does exist. The regulations permit the Commissioner to waive the deadline where the nonresident establishes that they acted reasonably and in good faith. Additionally, they must cooperate in determining the tax liability.
Nevertheless, treat the waiver as a repair, never as a plan. It requires the Commissioner's satisfaction, which is a discretionary standard. Therefore the correct approach is to file inside the window. In our experience, waiver requests supported by contemporaneous evidence succeed far more often than those written years afterwards.
Filing Status, Tax Numbers, Deadlines and the Residency Election
The administrative layer of Form 1040-NR trips up more couples than the technical layer. Furthermore, these rules differ from the American return in ways that are easy to miss.
Married Filing Separately Is Usually Compulsory
A nonresident cannot file jointly. Consequently, the IRS instructs a married nonresident to select married filing separately at the top of page one, even where the couple lives together and is not separated at all. The status reflects immigration and residency, not the state of the marriage. Consequently, every Form 1040-NR for a married spouse carries that status.
Meanwhile, the American spouse faces a parallel choice on their own return. They file separately too, unless they elect to treat the British spouse as a US resident.
Tax Numbers and Two Different Deadlines
Your British spouse cannot obtain a US social security number without US work authorisation. Therefore they apply for an individual taxpayer identification number instead, using Form W-7. The application is normally submitted with the first Form 1040-NR. We set out the practicalities in our guide to obtaining an ITIN for a non-US spouse.
The deadline then depends on the type of income, which surprises most filers. Where your spouse received wages subject to US income tax withholding, the return is due on 15 April. Otherwise it is due on the fifteenth day of the sixth month, which was 15 June 2026 for the 2025 year. Consequently, a British spouse with only rental income enjoys the later date automatically. An extension pushes the Form 1040-NR deadline further, though never the time to pay.
The Election to Be Treated as a US Resident
There is another path entirely, and occasionally it is the right one. The American spouse may elect to treat the British spouse as a US resident for the whole year. Consequently, the couple files a joint Form 1040 and abandons Form 1040-NR completely.
The attraction is the joint bracket structure and the standard deduction. However, the price is severe. Making the election exposes the British spouse's entire worldwide income to US tax. Their UK salary becomes taxable in America, their ISA loses its shelter, and their UK funds may become passive foreign investment companies. Therefore we usually advise against it where the British spouse has meaningful UK assets. Our detailed analysis sits in our guide to the section 6013(g) election and what it really costs.
When US Residency Arrives by Accident
Sometimes the choice is taken away. A British spouse who spends heavily in the United States may become a US tax resident under the day-count rules, entirely by accident. We explain the mechanics in our guide to the substantial presence test for Britons.
Where that happens mid-year, a dual-status return may be required instead. That combines a period on Form 1040-NR with a period on Form 1040, and it carries its own restrictions. Our note on the dual-status year covers the sequencing. Alternatively, the closer connection exception can preserve nonresident status where the day count permits.
The Two Layers American Guides Forget: HMRC and the States
American guides stop at the federal border. Nevertheless, two further layers apply to your British spouse, and both regularly cost more than the federal charge itself.
HMRC Taxes the Same Income Again
A UK resident pays UK tax on worldwide income, including US rents, dividends and interest. Therefore the American property appears on the UK Self Assessment foreign pages. Furthermore, the UK computation uses UK rules, which differ from the US ones in two expensive ways.
Firstly, the UK restricts finance costs on residential lettings to a basic-rate tax reduction. Secondly, the UK grants no depreciation deduction on the building. Consequently, the UK taxable profit is usually much larger than the US one, even on identical cash flows. Guidance on reporting overseas income sits on the HMRC pages covering foreign income.
Relieving the Double Charge
Relief comes through the UK foreign tax credit, claimed on the same Self Assessment return, under principles set out in the HMRC double taxation relief manual. Importantly, HMRC only credits US tax that the treaty permits the United States to charge. Therefore over-withheld US tax is not creditable in Britain.
That asymmetry is the practical reason to file Form 1040-NR promptly. Leave the excess with the IRS and neither country gives relief for it. Consequently, the money is simply lost.
The State Return Nobody Budgets For
Finally, remember that American states are not bound by the treaty. A Boston flat creates a Massachusetts nonresident filing obligation entirely separate from the federal one. Similarly, a New York property creates a New York return.
Consequently, the 15% treaty rate on dividends and the Article 14 exemption on business travel provide no protection at state level whatsoever. Moreover, state thresholds are frequently lower than the federal Form 1040-NR ones, and the Taxpayer Advocate Service cannot help with a state assessment. Therefore we always test the state position alongside the federal Form 1040-NR, never afterwards.
Worked Case Study: A London Couple and Six Unfiled Years
Consider Sarah and James, a married couple living in Islington. Sarah is an American citizen who has filed her US returns diligently. James is British, has never lived in the United States, and works for a London bank.
In 2019 James bought an investment flat in Boston in his sole name. He also holds a $560,000 portfolio of US shares. Nobody ever told him that either holding created an American obligation, still less an annual Form 1040-NR. Consequently, he had never filed Form 1040-NR when the couple came to us in 2026.
The Position We Found
The Boston flat produced $54,000 of gross rent in 2025. Allowable costs were $44,000, comprising mortgage interest of $19,000, property taxes of $6,800, depreciation of $12,700 and management and repairs of $5,500. Therefore the genuine net profit was $10,000.
Because no election had ever been made, the default treatment applied. The IRS was entitled to 30% of the gross rent, or $16,200, against real profit of $10,000. Meanwhile, his US broker had withheld 30% on $28,000 of dividends, taking $8,400 where the treaty permitted only $4,200. No W-8BEN had ever been lodged, so no Form 1040-NR had ever reclaimed the excess.
What the Delay Had Already Cost
The 2019 and 2020 years sat beyond the sixteen-month window and beyond the refund period. Consequently, the over-withheld dividend tax for those years was irrecoverable. That alone accounted for $8,400 of permanently lost money.
Furthermore, the deductions for those years were exposed under section 874. We assessed the waiver prospects as moderate at best, given the length of the delay and the absence of contemporaneous advice.
What We Did
We filed Form 1040-NR for 2022, 2023, 2024 and 2025. Each return carried the section 871(d) election at Schedule OI, together with the required property statement. Additionally, each carried a treaty claim reducing the dividend rate to the 15% permitted by Article 10.
We also lodged a W-8BEN with the broker to stop the over-withholding prospectively. Then we filed a waiver request for the earlier open years, supported by correspondence showing when James first learned of the obligation. Meanwhile, we amended two UK Self Assessment returns so that the foreign tax credit matched the corrected US figures, and we registered him for the Massachusetts nonresident return.
The Outcome
The recovered dividend withholding across the open years came to $12,600. The rental charge fell from $16,200 to $1,043 for 2025, and to comparable figures for the other open years. Consequently, the annual saving going forward exceeds $19,000 once the dividend position is included. Four Form 1040-NR filings produced that result.
One further relief mattered. James had sold $180,000 of US shares at a $47,000 gain in 2024, and had assumed a US charge applied. Under Article 13, that gain was taxable only in Britain, so no US tax arose at all. Sarah's own position simplified too. She continued filing as married filing separately, and we confirmed that the residency election would have cost the household far more than it saved.
How TaxYork Can Help With Form 1040-NR
We prepare both sides of the return for cross-border couples, and that is the point. Preparing Form 1040-NR without modelling the UK Self Assessment position produces a technically correct return that still costs the household money.
Our work begins with a source analysis. We identify every item of your British spouse's income that the United States can reach, and we place each item in the correct bucket. Consequently, we can tell you quickly whether a return is required at all, which is frequently the most valuable answer we give.
Where a return is required, we prepare it in full. That includes the section 871(d) election and its supporting statement, Schedule NEC for passive income, Schedule OI, treaty claims with the necessary disclosure, and the Form W-7 application where a tax number is needed. Additionally, we handle refund claims for over-withheld amounts before the three-year window closes, and we lodge the withholding certificates that prevent the problem recurring.
Furthermore, we coordinate the American spouse's position at the same time. That covers the married filing separately computation, the residency election analysis, and any foreign account reporting triggered by joint accounts. Where the couple's affairs span companies, property or share schemes, our cross-border planning team models the whole structure rather than one form in isolation.
Conclusion
Form 1040-NR rewards precision and punishes delay. Most British spouses owe nothing and file nothing, and establishing that fact confidently is worth doing properly. However, a British spouse holding American property or American investments sits in a different position entirely.
For that spouse, four decisions dominate. Firstly, make the section 871(d) election so that US property is taxed on net profit rather than on gross rent. Secondly, claim the treaty rates, because 15% on dividends and nil on interest are rights, not concessions. Thirdly, lodge a W-8BEN so the correct rate applies at source. Fourthly, file inside the sixteen-month window, because section 874 removes the deductions altogether once it closes.
Ultimately, the cost of getting a Form 1040-NR wrong is not a penalty. Rather, it is a permanently higher rate of tax on income that should have been lightly taxed. Act while every year is still open.
Contact Us
Speak to us before your British spouse's next US filing deadline. You can book a consultation with our cross-border team, email hello@taxyork.com, or telephone 020 3488 8606. We will confirm whether a Form 1040-NR is required, quantify the treaty position, and recover any tax already over-withheld.
Disclaimer
This article provides general information about Form 1040-NR and US-UK tax compliance. It does not constitute tax advice for any particular person or situation. You should not act on it without professional guidance. Tax law, rates, treaty positions and thresholds change frequently. Figures cited are current as at August 2026. Always obtain specific professional advice on your own circumstances before filing or making any election.