Most nonresident aliens start with the wrong question. The question is not which form to file, because the answer is almost always Form 1040-NR. The question is which bucket each dollar of U.S. income falls into, because that classification drives the entire result. A nonresident alien return sorts U.S. source income into effectively connected income and FDAP income, and those two buckets are taxed under completely different systems. Two people with identical gross receipts from the United States can owe dramatically different tax based on nothing but that classification.
Who Must File Form 1040-NR, and Who Is a Nonresident Alien?
You must file Form 1040-NR if you are a nonresident alien who was engaged in a U.S. trade or business during the tax year, or if you had U.S. source income on which the U.S. tax liability was not fully satisfied by withholding at the source. The trade or business test applies even if the activity produced no income and even if a treaty ultimately exempts the profit. One common exception runs the other way: nonresident students, teachers, and trainees present on F, J, M, or Q visas who have no income subject to U.S. tax file Form 8843 instead of a Form 1040-NR.
A nonresident alien is anyone who is not a U.S. citizen and who fails both residency tests: the green card test and the substantial presence test. The substantial presence test counts 31 days in the current year plus a weighted 183 days, calculated as current year days, plus one third of prior year days, plus one sixth of second prior year days. If you crossed that line partway through the year, you are not a straightforward 1040-NR filer at all, you are a dual-status alien filing for two periods under two sets of rules.
Filing voluntarily is also worthwhile when a payer withheld the full 30% but a treaty entitled you to less, because the return is the only mechanism to recover the difference. If you do not have a Social Security number, you will need to obtain an ITIN on Form W-7, generally submitted with the return itself.
What Is the Difference Between ECI and FDAP Income?
ECI is income connected with the conduct of a U.S. trade or business, and it is taxed at graduated rates on a net basis after allowable deductions. FDAP income is passive-type U.S. source income, and it is taxed at a flat 30% on the gross amount with no deductions, unless an income tax treaty reduces the rate. The two are reported in different places on the same return: ECI on the main body of Form 1040-NR, FDAP on Schedule NEC (income not effectively connected).
The practical consequence is severe. A nonresident who owns a U.S. rental property and treats the rent as FDAP pays 30% of gross rent, with no deduction for mortgage interest, property tax, insurance, repairs, or depreciation. The same property, with the same cash flow, may generate little or no tax if the income is instead treated as effectively connected. IRC §871(d) provides an election to treat income from U.S. real property as effectively connected specifically so that expenses become deductible. That election is one of the highest-value decisions on a nonresident return, and it is routinely missed. It is not free of consequence, though: once made, the §871(d) election binds every subsequent tax year and can be revoked only with IRS consent.
One Schedule NEC item gets overlooked more than any other. Under IRC §871(a)(2), a nonresident who is present in the United States for 183 days or more during the tax year is taxed at 30% on the excess of U.S. source capital gains over capital losses, reported on Schedule NEC rather than on Schedule D. Timing matters in the other direction too: IRC §864(c)(6) recharacterizes deferred payments received in a later year, including certain pension distributions, as effectively connected income if the income would have been effectively connected when it was earned.
What Makes Income U.S. Source in the First Place?
Only U.S. source income enters the Form 1040-NR system at all (along with foreign source income that is effectively connected in narrow circumstances). Sourcing is determined by the rules in IRC §§861 through 865, and it turns on the nature of the income, not on where the money was paid or which bank received it.
Where Income Is Sourced Under IRC §§861-865
Reference- Compensation for services: sourced where the services are performed. A foreign employer paying into a foreign account does not make the income foreign source if the work happened in the United States.
- Rents and royalties: sourced where the property is located or used.
- Interest: generally sourced by the residence of the payer.
- Dividends: generally sourced by the place of incorporation of the paying corporation.
- Sale of real property: sourced where the property is located.
- Sale of personal property: generally sourced by the residence of the seller, with major exceptions for inventory, depreciable property, and U.S. real property interests.
Two exclusions matter enormously in practice. Interest on U.S. bank deposits paid to a nonresident is generally not subject to the 30% tax, and qualified portfolio interest is exempt under IRC §871(h).
Which Deductions, Credits, and Filing Statuses Can a Nonresident Claim?
Nonresident aliens generally cannot claim the standard deduction, cannot file a joint return, and cannot use head of household filing status. Form 1040-NR filers are limited to single, married filing separately, or, for a narrow group (residents of Canada, Mexico, and South Korea, and U.S. nationals), qualifying surviving spouse. That last status is available only where the filer's spouse died in one of the two preceding tax years and the filer has not remarried, and it allows the joint return rates. Deductions are permitted only to the extent they are connected with income that is effectively connected with a U.S. trade or business, and even then the list in IRS Publication 519 is narrow: ordinary and necessary business expenses, the qualified business income deduction, losses tied to U.S. source income, IRA contributions, student loan interest, and self-employed retirement contributions, among a few others.
Two items on that list are commonly stated backwards. IRC §873(b)(1) allows casualty and theft losses under §165(c)(3) for property located in the United States and not connected with a trade or business, meaning personal-use property, and post-TCJA those losses are allowed only when attributable to a federally declared disaster. IRC §873(b)(2) affirmatively allows a charitable contribution deduction for gifts to U.S. organizations; it is contributions to foreign organizations that are not deductible, so a nonresident is not shut out of charitable giving deductions entirely.
There is one notable treaty exception. Students and business apprentices eligible for the benefits of Article 21(2) of the United States-India income tax treaty may claim a standard deduction, computed on the dedicated worksheet the IRS publishes in Publication 519. The allowable amount is limited and is reduced by deductions already claimed, so it is not simply the full figure a citizen would take. No other treaty grants a comparable standard deduction to students, and the exception does not extend to Indian nationals in the United States on ordinary work visas.
Credits are similarly restricted. Most refundable and family-based credits are unavailable to nonresidents, though the return always allows credit for tax already withheld.
How Does Withholding Work, and How Do You Get It Back?
FDAP income is collected at the source. A U.S. payer acting as withholding agent under IRC §1441 must withhold 30% of the gross payment unless the recipient has provided documentation establishing a lower rate. That documentation is Form W-8BEN, which the recipient gives to the payer, not to the IRS. It certifies foreign status and, when a treaty applies, claims the reduced rate. A W-8BEN claiming treaty benefits generally requires a U.S. taxpayer identification number, which is why the ITIN and the withholding rate are practically linked.
At year end, the withholding agent issues Form 1042-S reporting the gross income paid and the tax withheld by income code. Those amounts flow onto Schedule NEC, and the tax withheld is claimed as a credit against the total liability computed on Form 1040-NR. Wage income, by contrast, is reported on Form W-2 and treated as ECI in the main body of the return, exactly as it would be on a Form 1040.
How Is a Nonresident Taxed on Selling U.S. Real Estate?
Gain on the disposition of a U.S. real property interest is treated as effectively connected income under IRC §897, regardless of whether the seller conducted any other U.S. business activity. That means graduated rates on the net gain, with basis and selling costs taken into account, not a flat 30% on the sale price.
Collection is handled separately through FIRPTA. Under IRC §1445, the buyer is generally the withholding agent and must withhold 15% of the amount realized, reporting it on Form 8288 with a Form 8288-A statement to the seller.
Before assuming 15%, check the buyer-residence exceptions, which apply where the buyer acquires the property for use as a residence for the buyer or a family member. No withholding is required at all when that residence test is met and the amount realized is $300,000 or less. The rate drops to a reduced 10% when the residence test is met and the amount realized is over $300,000 but not more than $1,000,000. A nonresident selling a $280,000 home to an owner-occupant therefore faces no FIRPTA withholding at all.
Outside those exceptions, the 15% is applied to the gross sales price, not the gain, so on a property with modest appreciation the withholding routinely exceeds the actual tax. Two remedies exist: apply for a withholding certificate on Form 8288-B before or at closing to reduce the amount withheld, or file the Form 1040-NR and claim the excess as a refund.
When Is Form 1040-NR Due, and Where Do You File It?
The due date depends on how you earned the income. If you were an employee who received wages subject to U.S. income tax withholding, or you maintained an office or place of business in the United States, the return is due the 15th day of the 4th month after your tax year ends, generally April 15. If neither condition applies, the return is due the 15th day of the 6th month, generally June 15.
Form 4868 extends the filing deadline, but not the obligation to pay, and interest runs from the original due date. Form 1040-NR is filed by mail or electronically at the service center designated in the current Form 1040-NR instructions, which is not the same address a citizen uses.
One deadline carries an unusually harsh consequence. To claim deductions and credits against effectively connected income, the return generally must be filed within 16 months of its original due date. File later than that and the IRS can compute the tax on gross effectively connected income with no deductions allowed, which converts a modest liability into a large one. For a chronically late nonresident filer, that rule, not the failure-to-file penalty, is usually the biggest exposure.
It is not absolute, and two provisions are worth knowing before conceding the deductions. Regulations §1.874-1(b)(2) permits a waiver of the deadline where the taxpayer establishes, based on the facts and circumstances, that they acted reasonably and in good faith in failing to file. Regulations §1.874-1(b)(6) allows a protective return, filed on time reporting no effectively connected income, that preserves the right to deductions if the IRS later determines effectively connected income existed. Credits under IRC §§31, 32, 33, and 34, including tax already withheld at the source, are preserved under Regulations §1.874-1(a) regardless of when the return is filed.
When Do You Need Form 8833 for a Treaty Position?
You must file Form 8833 when you take a treaty-based return position that overrides or modifies a provision of the Internal Revenue Code, as required by IRC §6114. Dual-resident taxpayers who use a treaty tiebreaker to be treated as a nonresident disclose under Regulations §301.7701(b)-7 on the same form. The penalty for failing to disclose is $1,000 per failure for an individual and $10,000 for a C corporation under IRC §6712.
Not every treaty benefit requires the form. The regulations under §6114 waive disclosure for a number of routine items, including many treaty-reduced withholding rates on FDAP income already reported on Form 1042-S. Regulations §301.6114-1(c)(1)(iv) specifically waives reporting where a treaty reduces or modifies the taxation of income from dependent personal services, pensions, annuities, and social security, which covers most employees claiming a treaty benefit on wages. A second waiver in Regulations §301.6114-1(c)(2) covers an individual whose otherwise-reportable treaty items do not exceed $10,000 in the aggregate for the year. Positions that generally do require disclosure include claiming that business profits are exempt because you have no U.S. permanent establishment, claiming a treaty exemption for independent personal services income, and using a residency tiebreaker.
Bottom Line
Form 1040-NR is not a simplified Form 1040. It is a return built on a classification decision made before any number is entered. Get income into the ECI bucket where the facts and elections support it and you are taxed on profit at ordinary rates. Leave it in the FDAP bucket and you are taxed on gross receipts at 30% with no relief except a treaty. The fix is almost always the same: file the return, apply the correct sourcing and classification, and claim back what the withholding system took in advance.
Our international tax and cross-border tax teams prepare nonresident returns, evaluate the §871(d) and treaty elections, and handle FIRPTA withholding certificates before closing rather than after. Have questions about Form 1040-NR or nonresident alien taxation? Contact TS CPA for a free consultation. We respond within the same day.