US Tax Preparation for Nonresidents: 2026 Filing Guide

If you live outside the United States but earn money from US sources, you may have a US federal tax filing obligation even if you have never visited the country. This guide explains who counts as a nonresident for US tax purposes, which income is taxed, which return applies, and what to gather before you or a preparer files.

This is general information for the 2025 tax year (returns filed in 2026). It is not advice for your specific situation, and tax rules change, so confirm current rules with the IRS sources listed at the end.

Step 1: Confirm you are a nonresident alien for tax purposes

US tax residency for non-citizens is decided by two tests, not by visa type alone.

Green card test. If you held a green card at any time during the year, you are generally a US tax resident.
Substantial presence test. You are a resident if you were physically present in the US for at least 31 days in the current year and at least 183 days over three years, counting all days in the current year, one third of the days in the prior year and one sixth of the days in the year before that.

Some people are exempt from counting days, such as certain students, teachers and trainees on F, J, M or Q visas. People who meet neither test are nonresident aliens. Some people are dual-status in the year they arrive or leave, and they file differently.

Step 2: Identify which of your income is US-source

Nonresident aliens are taxed only on US-source income. The IRS splits that income into two categories, and they are taxed very differently.

Income type	Common examples	How it is generally taxed
Effectively connected income (ECI)	Wages for work performed in the US, profits from a US trade or business, partnership income from a US business	Graduated rates after allowable deductions, reported on Form 1040-NR
Fixed, determinable, annual or periodical income (FDAP)	US dividends, certain interest, rents, royalties	Flat 30% on the gross amount unless a tax treaty sets a lower rate, usually collected through withholding

Where the work is physically performed generally decides whether wages are US-source. A freelancer who lives abroad and works for a US client from abroad is often not earning US-source wages, but the facts matter and should be checked.

Step 3: Decide which return you need

Form 1040-NR is the individual return for nonresident aliens who must file, including those with ECI, those who want a refund of over-withheld tax, and those claiming certain treaty benefits.
Form 5472 with a pro forma Form 1120 applies to a US single-member LLC owned by a foreign person. That is a filing for the LLC, separate from any personal 1040-NR. See our Form 5472 and pro forma 1120 guide.
Form 1065 applies when a US LLC has two or more members and is taxed as a partnership. Foreign partners usually receive a Schedule K-1 and may also need to file Form 1040-NR.

If you own a US LLC that earned no US income at all, you may still have the entity filing above. Our guide to US tax filing for foreign LLC owners with no US income covers that case.

Step 4: Know the deadlines

For calendar-year individuals filing for tax year 2025:

April 15, 2026 for calendar-year Form 1040-NR filers who received wages subject to US income tax withholding.
June 15, 2026 for calendar-year Form 1040-NR filers who did not receive wages subject to US income tax withholding.

You can request an automatic extension of time to file with Form 4868, but an extension to file is not an extension to pay. Interest and late payment penalties can still apply to any tax owed after the original due date.

Step 5: Understand the limits on deductions and credits

Nonresident returns are more restricted than resident returns:

Most nonresident aliens cannot claim the standard deduction. A limited treaty exception exists for certain students and business apprentices from India.
Nonresident aliens generally cannot file jointly with a spouse.
Itemized deductions are limited, mainly to state and local income taxes on ECI, charitable gifts to US organizations and certain casualty losses.
Many credits available to residents are not available, or are available only in narrow cases.

Step 6: Check whether a tax treaty applies

The US has income tax treaties with many countries, including the United Kingdom and Canada. A treaty can reduce withholding on dividends or royalties, or exempt certain wages, scholarships or business profits.

To claim treaty benefits you usually provide Form W-8BEN to the payer, and where required you disclose the treaty position on Form 8833 with your return. Treaty articles are specific and conditional, so read the actual treaty text rather than assuming a benefit applies.

Step 7: Get a taxpayer identification number

A nonresident who files a return needs an SSN or an Individual Taxpayer Identification Number (ITIN). If you are not eligible for an SSN, you apply for an ITIN on Form W-7, usually together with your first return. A Certified Acceptance Agent can verify identity documents so you do not have to mail your original passport.

Step 8: Do not forget state taxes

State rules are separate from federal rules. Some states tax nonresidents on income earned within the state, and a few states have no individual income tax at all. If you performed work in a state or own rental property there, check that state's nonresident filing rules.

Common mistakes we see

Filing Form 1040 instead of Form 1040-NR, and claiming the standard deduction in error.
Assuming no filing is needed because tax was withheld. A return may be required to report ECI or to claim a refund.
Missing the entity filing for a foreign-owned US LLC while focusing only on personal tax.
Claiming a treaty benefit without the required disclosure.
Using the wrong deadline (April 15 versus June 15).

Document checklist

Passport and visa history, with travel dates to count US days
Forms W-2, 1042-S, 1099 and any Schedule K-1
Prior-year US returns, if any
ITIN or SSN, or a completed Form W-7
Records of US business income and expenses
Bank statements showing US-source payments
Details of the treaty article you plan to rely on

Common questions

Do I have to file if all my US tax was withheld? Not always. Some nonresidents with only FDAP income fully withheld at the correct rate have no filing requirement, but you must file to claim a refund, and you must file if you had ECI.

Can I e-file Form 1040-NR? Yes, Form 1040-NR can be e-filed through authorized software or a preparer in most cases.

Does owning a US LLC make me a US tax resident? No. Residency depends on the green card and substantial presence tests, not on company ownership.

How Gullia Filing helps

Our team prepares Form 1040-NR returns, Form 5472 entity filings and ITIN applications for founders and individuals outside the US. If you want your return prepared and reviewed before it is filed, see our US tax preparation services for nonresidents and businesses. We cannot promise a refund or a particular IRS result, but we will explain every position we take in writing.