Quick answer

You must file Form 1040-NR if you are a nonresident alien for U.S. tax purposes and during the tax year you: (1) were engaged in a trade or business in the United States and had income effectively connected with that business (ECI), (2) received U.S.-source income subject to U.S. tax (including FDAP — fixed, determinable, annual, or periodical income), or (3) need to claim a refund or a reduced withholding rate under a tax treaty. For official rules, see IRS Form 1040-NR and Publication 519 (U.S. Tax Guide for Aliens) (IRS.gov).

How U.S. tax residency is determined

Whether you must file Form 1040-NR starts with your tax residency status. The IRS uses two main tests:

  • Green card test: You are a U.S. resident for tax purposes if you are a lawful permanent resident at any time during the year. (IRS Publication 519)
  • Substantial presence test: You are a resident if you were physically present in the U.S. for at least 31 days in the current year and 183 days over a three-year weighted formula. (IRS Publication 519)

If you do not meet either test, you are generally a nonresident alien and may need Form 1040-NR when you have U.S.-sourced income. For details on residency rules, see IRS Publication 519 (https://www.irs.gov/publications/p519).

Types of U.S. income that trigger filing

Nonresident aliens are taxed differently depending on the type of U.S. income:

  • Effectively Connected Income (ECI): Income from a U.S. trade or business (wages, business income) is taxed on a net basis at graduated rates and is reported on Form 1040-NR. If you earned wages reported on Form W-2 and taxes were withheld, you generally still file to reconcile withholding and claim refunds. (IRS Form 1040-NR)

  • FDAP income: Passive U.S.-source income such as interest, dividends, rents, royalties, and some pensions is generally subject to a flat 30% withholding unless reduced by a tax treaty. FDAP is often withheld at source and may or may not require filing depending on circumstances, but filing Form 1040-NR is necessary to claim treaty reductions or refunds. (IRS Publication 519)

  • Other triggers: Sale of U.S. real property interests, partnership income effectively connected in the U.S., and certain income of scholars or students may also create filing requirements.

Deadlines and filing method (what to watch for)

Deadlines for Form 1040-NR vary by situation:

  • If you received wages subject to U.S. income tax withholding, the due date is generally April 15 (or the next business day if that date is a weekend or holiday).
  • If you did not receive wages subject to withholding, the due date is typically June 15.

Deadlines can shift year to year and the IRS may publish updated due dates; always confirm the current year deadline at the IRS Form 1040-NR page (https://www.irs.gov/forms-pubs/about-form-1040-nr) and in Publication 519. Extensions: You can request an extension to file, but an extension to file is not an extension to pay. If you expect tax due, pay by the original deadline to avoid penalties and interest.

Electronic filing: The IRS and software providers increasingly accept e-filing for Form 1040-NR, but some taxpayers may still need paper filing depending on visa/status or treaty claims. Check current IRS guidance and available tax software or work with a tax pro.

Tax treaties and withholding — when treaty benefits require filing

Many nonresident aliens are eligible for reduced rates or exemptions under a U.S. tax treaty with their home country. To claim benefits at source, you may submit Form W-8BEN to payers; to claim a refund or a treaty-based deduction on your annual return you must file Form 1040-NR. Because treaty language varies, I recommend reviewing the specific treaty text and the IRS explanation in Publication 515 and Publication 901, and consider professional review. See our practical guide on how treaties affect international income: “How Tax Treaties Affect International Income and Withholding” (finhelp.io guide).

Practical decision checklist — should you file Form 1040-NR?

  1. Are you a nonresident alien for the tax year? If no, do not use 1040-NR; see resident filing rules.
  2. Did you earn wages in the U.S., receive a W-2, or were you engaged in U.S. trade or business? If yes, file 1040-NR.
  3. Did you receive U.S.-source FDAP income (interest, dividends, royalties, rents)? If yes, determine if 30% withholding satisfied your U.S. tax or if a treaty reduces that rate — file 1040-NR to claim refunds or treaty benefits.
  4. Did you sell U.S. real property, receive partnership income tied to a U.S. activity, or need to claim a refund of overpayment? File 1040-NR.

If you answered yes to any of the above, you likely need Form 1040-NR. For detailed line-by-line help or special cases (students, scholars, dual-status years), consult Publication 519 or a tax professional.

Common real-world examples

  • Visiting researcher on a J-1 visa who was paid wages for six months: Even if temporary, wages sourced to the U.S. are effectively connected — file Form 1040-NR to report wages and reconcile withholding.
  • Foreign investor receiving U.S. dividends and interest: If the payer withheld 30% and a tax treaty reduces the rate, file Form 1040-NR to claim the lower treaty rate or a refund if you were over-withheld.
  • Nonresident with sale of U.S. real estate: Dispositions of U.S. real property interests often trigger filing and special withholding rules (FIRPTA) — Form 1040-NR reports the gain and computes tax due.

Common mistakes and how to avoid them

  • Filing the wrong return: Residents use Form 1040; nonresidents use 1040-NR. Don’t combine worldwide income on Form 1040-NR; only U.S.-sourced income or effectively connected items belong there. See our guide “Form 1040-NR — U.S. Nonresident Alien Income Tax Return” for comparison (finhelp.io article).
  • Missing treaty provisions: Some taxpayers assume treaty relief applies automatically. In practice, you must claim treaty benefits correctly on the return or via withholding forms. Keep treaty documents and residency proofs.
  • Ignoring state taxes: Filing Form 1040-NR addresses federal taxes only; many states have their own filing rules for nonresidents with U.S. source income.

Forms and supporting documents you may need

  • Form 1040-NR (the return itself).
  • Form W-2 (wages), Forms 1099 (certain U.S. income), or withholding certificates.
  • Form W-8BEN (to certify foreign status to payers) or Form 8233 (exemption from withholding for personal services by a nonresident alien individual) if applicable. See our comparison of withholding forms: “Form W-9 vs W-8BEN” (finhelp.io guide).
  • Treaty documentation or U.S. taxpayer identification number (ITIN) application materials if you do not have an SSN.

In my practice — pragmatic tips

  • Get an ITIN early: If you expect to claim treaty benefits or refunds, apply for an ITIN well before filing deadlines; missing an ITIN can delay refunds.
  • Keep source documentation: Copies of pay stubs, grant letters, or contracts help classify income as ECI or FDAP.
  • When in doubt, file: Filing Form 1040-NR to claim an over-withheld amount is typically low risk and often results in a refund.

Penalties and enforcement

Failure to file or pay can trigger penalties and interest. Penalties vary by the amount and timeliness, and interest accrues on unpaid taxes. For exact penalty rules and amounts, consult the IRS website and Publication 509 and 519.

Where to get authoritative guidance

Final checklist before you file

  • Confirm your residency status under Publication 519.
  • Collect all U.S. income documents (W-2, 1099s, statements).
  • Review any applicable tax treaty articles and record your claim correctly.
  • Apply for ITIN/SSN if required.
  • File by the appropriate deadline and pay any tax due to avoid penalties.

Professional disclaimer: This article provides general education about U.S. federal tax filing for nonresident aliens and does not substitute for individualized tax advice. For complex situations (dual-status years, treaty interpretation, business income), consult a qualified tax professional or the IRS resources cited above.

Authoritative sources

Related FinHelp resources

(Last reviewed: 2025).