Form 1040NR is the US tax return filed by non-resident aliens — people who are not US citizens, Green Card holders or US tax residents — who nonetheless have US-source income. For a UK resident, that typically means US rental property, a US business interest, or US investment income. The way that income is taxed splits into two very different regimes — and choosing the wrong characterisation can mean paying 30% on gross income instead of graduated rates on net profit. The good news is that the US/UK treaty and a key election usually cut the bill sharply, provided you claim them correctly. Here is who files Form 1040NR, how the tax actually works, the treaty rates, and where UK residents most often need it — whether you own a US rental, sold US property, or just want to reclaim tax that was over-withheld.
Who is a non-resident alien?
You are a non-resident alien (NRA) for US tax if you are not a US citizen, not a Green Card holder, and do not meet the substantial-presence test (a day-counting test for time spent in the US). A British national living in the UK with no US status, who happens to own a US rental property or earns US-source income, is the classic NRA who files Form 1040NR. By contrast, US citizens and Green Card holders file the ordinary Form 1040 on worldwide income — see how US tax returns work for Americans in the UK.
Two regimes: effectively connected income vs FDAP
The key to Form 1040NR is that US-source income of a non-resident is taxed in one of two ways, depending on its character:
- Effectively Connected Income (ECI) — income connected with a US trade or business (including, by election, US rental property). It is taxed at the normal graduated US rates after deductions, much like a US person's income.
- FDAP income — Fixed, Determinable, Annual or Periodical income such as dividends, interest, rents and royalties not connected to a US business. It is generally taxed at a flat 30% on the gross amount, with no deductions — unless a treaty reduces the rate.
How the US/UK treaty cuts the rate
This is where the US/UK tax treaty helps a UK resident NRA. The treaty typically reduces the 30% FDAP withholding on US dividends to 15%, and often reduces withholding on interest and royalties to 0%. A UK resident receiving US dividends should therefore not be over-withheld at 30% — the treaty rate applies if the right paperwork (such as a Form W-8BEN to the payer) is in place. The official treaty texts are on the IRS US-UK tax treaty page.
US rental property: the net election
US rental income earned by a non-resident is, by default, FDAP — taxed at 30% on the gross rent with no deductions, which is brutal for a landlord with a mortgage and expenses. Fortunately, a non-resident can elect to treat US real-property income as effectively connected, which means it is taxed at graduated rates on the net profit after deductions like mortgage interest, repairs, management fees and depreciation. For most UK-resident owners of US rentals, making this election is essential — and it is reported on Form 1040NR.
Selling US property: FIRPTA withholding
When a non-resident sells US real estate, FIRPTA (the Foreign Investment in Real Property Tax Act) generally requires the buyer to withhold a percentage of the gross sale price and remit it to the IRS, as a prepayment against the seller's US tax. The seller then files Form 1040NR to report the actual gain and reclaim any over-withheld amount. UK residents selling US property need to plan for this withholding and the reclaim process, which our broader guide to US property owned by UK residents touches on alongside the wider picture.
Deductions and credits on Form 1040NR
Non-resident aliens are limited in the deductions and credits they can claim. Generally there is no standard deduction (with limited exceptions), and personal credits are restricted. Deductions are mainly available against effectively connected income — which is another reason the ECI election on rental property matters so much. The result is that Form 1040NR is less generous than Form 1040, and getting the income characterised correctly is where the tax is won or lost.
The dual-status year
There is an important overlap case: the year you arrive in or leave the US, you may be a 'dual-status' taxpayer — a non-resident for part of the year and a resident for the rest. In such a year you may file both a 1040NR (for the non-resident part) and a 1040 (for the resident part). These transition years are technical and easy to get wrong, so they usually warrant professional help rather than software.
When does a UK resident need Form 1040NR?
- You own and rent out US property and are not a US person.
- You have US business income not run through a US entity that files separately.
- You receive US-source income that was over-withheld and you want to reclaim it.
- You sold US real estate and had FIRPTA tax withheld.
- You are in a dual-status arrival or departure year.
How to hold US property: your name or an entity?
Non-residents often ask whether to own US property personally or through a company (US LLC, US corporation, or even a foreign company). Each route has very different US tax, filing and estate-tax consequences. Holding personally is simplest and uses the rules above, but it exposes the property to US estate tax on death, where the non-resident exemption is strikingly low. Holding through an entity can change the income, gain and estate-tax picture — sometimes helpfully, sometimes not — and adds its own filings. There is no one-size answer; the structure should be chosen before you buy, with both the US and UK consequences modelled together.
State tax on your US rental
Federal Form 1040NR is not the whole story for a US rental. The state where the property sits usually taxes the rental income too, and will want its own non-resident state return. State rules, rates and thresholds vary widely and are not covered by the US/UK treaty or the federal mechanics above. So a UK resident with, say, a New York rental may face a federal 1040NR and a New York non-resident return — budget for both, not just the federal filing.
Documenting treaty claims: Form W-8BEN
To actually receive reduced treaty withholding on US-source income, a non-resident usually has to give the US payer a Form W-8BEN certifying their foreign status and treaty eligibility. Without it, the payer must withhold the full 30% on FDAP income such as dividends. If you have been over-withheld because no W-8BEN was on file, filing Form 1040NR is how you reclaim the difference. Keeping your W-8BEN current with each US payer is the simplest way to ensure the treaty rate is applied at source rather than reclaimed later.
Penalties for not filing 1040NR
Ignoring a Form 1040NR obligation can be costly. If you do not file, the IRS can deny the deductions and elections (like the net rental election) that make the tax bearable, potentially taxing you on gross income at 30% with no offsets, plus late-filing and late-payment penalties and interest. Because the cost of getting it wrong is so asymmetric — a correct return can slash the tax, a missing one can inflate it — filing properly and on time is well worth it.
Do you also owe UK tax on the same US income?
If you are a UK resident filing a 1040NR on US income, remember that the UK also taxes you on your worldwide income — so the same US rental profit or US dividend is usually reportable in the UK too. The US/UK treaty and the UK's foreign tax credit mechanism are what stop you being taxed twice: typically the US taxes the US-source income first, and the UK gives credit for the US tax paid. Coordinating the two returns so the credit lands correctly is essential, and is exactly where treating the US and UK filings as one joined-up exercise pays off.
Common 1040NR mistakes
- Accepting 30% withholding on US dividends instead of the 15% treaty rate (no W-8BEN on file).
- Failing to make the net election on US rental income and being taxed on gross rent.
- Forgetting the state non-resident return on US rental income.
- Not reclaiming over-withheld FIRPTA tax after selling US property.
- Mishandling a dual-status arrival or departure year.
- Overlooking that the same income may also be UK-taxable, and missing the credit.
Deadlines and getting it right
Form 1040NR deadlines depend on the type of income and whether you had US wages, but they broadly track the US filing calendar, and extensions are available — see our US tax deadlines guide for the dates. Because the difference between FDAP and effectively connected treatment can multiply or slash the tax, and because the treaty and elections have to be claimed correctly, Form 1040NR is an area where specialist preparation reliably pays for itself — the fee is typically a small fraction of the tax a correctly-prepared return saves over filing it wrong or not at all.
