A company formed outside the United States can acquire a filing obligation here without opening an office or sending anybody to live here.
What creates it is income connected with a trade or business in the country, and that connection can arise from arrangements a founder would not think of as a presence at all: an agent, a warehouse, a dependent contractor.
This covers who has to file, the distinction the return turns on, how treaty positions and withholding interact with it, and why establishing the position early matters more than the mechanics of the form.
Form 1120-F, U.S. Income Tax Return of a Foreign Corporation, is filed by foreign corporations that conduct business in the United States or receive certain types of U.S.-source income. Filing requirements exist even when no U.S. tax is owed. Failure to file can result in substantial penalties and the loss of certain deductions.
Who Must File Form 1120-F
A foreign corporation must file Form 1120-F if:
- It was engaged in a trade or business in the United States at any point during the tax year (regardless of whether it had taxable income from that business), OR
- It had U.S.-source income (interest, dividends, royalties, rents, or other fixed or determinable annual or periodical income, FDAP) that is subject to U.S. withholding tax at source
Note: If a foreign corporation had no income, no assets, and no activities in the U.S. at any time during the year, it generally does not need to file.
The question is not whether a foreign company has an office here. It is whether it has income connected with a trade or business here, and that can arise from activity a founder would not think of as a presence at all. Establish the position before the year end rather than assuming absence of premises means absence of obligation.
Ankit Sarawagi, CPA, CA, MBA · LinkedInECI vs. FDAP Income, The Core Distinction
| Type | Description / Tax Treatment |
|---|---|
| Effectively Connected Income (ECI) | Income that is connected to the foreign corporation's U.S. trade or business. Taxed at graduated U.S. corporate tax rates (currently 21% flat). Reported on Form 1120-F and deductions are allowed. |
| Fixed/Determinable Annual/Periodical (FDAP) Income | Passive U.S.-source income (dividends, interest, royalties, rents, certain gains). Generally taxed at a 30% flat rate (or lower treaty rate) withheld at source. Reported on Form 1099 or 1042-S by the payer. |
Treaty Elections and Benefits
If the foreign corporation's home country has a tax treaty with the United States, it may be entitled to:
- Reduced withholding rates on FDAP income (e.g., 15% or 5% on dividends instead of 30%)
- Exemption from U.S. tax on certain business profits if the corporation does not have a U.S. permanent establishment (PE)
- Exemption from branch profits tax
To claim treaty benefits, the corporation must file Form 1120-F and check the treaty election boxes on Page 1. Treaty benefits are not automatic, they must be affirmatively claimed.
Protective Return Filing
A foreign corporation that believes it has no taxable ECI may still file a 'protective return', a Form 1120-F with zero income, to preserve the right to claim deductions if the IRS later asserts that ECI exists. Without a timely protective return, the foreign corporation loses the right to deductions and credits if the IRS audits and finds ECI.
Pro Tip: If your foreign corporation had any U.S. activities during the year, even a single U.S. client visit, a U.S. bank account, or U.S.-source royalties, file a protective return. The cost is low; the risk of not filing is unlimited.
Branch Profits Tax (Section 884)
In addition to the regular corporate income tax on ECI, foreign corporations with a U.S. branch are subject to the branch profits tax (BPT) of 30% (or lower treaty rate) on 'dividend equivalent amounts', essentially, profits removed from the U.S. branch that are not reinvested in U.S. assets. The BPT is calculated on Form 1120-F and is designed to put U.S. branches of foreign corps on equal footing with U.S. subsidiaries that pay dividends to foreign parents.
Filing Deadline
Form 1120-F is due by the 15th day of the 6th month after the close of the tax year (June 15 for calendar-year foreign corporations). A 6-month extension is available via Form 7004 (extends to December 15). If the foreign corporation has an agent in the U.S. who is authorized to accept service of process, it can request a 3-month extension to the standard April 15 date and then a further extension to October 15.
State Filing Obligations
A foreign corporation with a U.S. trade or business may also be required to file state income tax returns in each state where it conducts business (nexus). States have their own nexus rules, and some states impose gross receipts taxes or minimum taxes regardless of profitability.
Penalties for Late or Non-Filing
| Situation | Penalty |
|---|---|
| Failure to file Form 1120-F | 5% per month up to 25% of unpaid tax; potential loss of deductions and credits |
| Failure to claim deductions timely | Under Treas. Reg. 1.882-4, deductions are disallowed if not claimed on a timely filed return (including extensions). No deductions = tax on gross income. |
| Failure to pay estimated taxes | Underpayment penalty on U.S. tax liability |
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Frequently Asked Questions
Does a foreign corporation that sells products online to U.S. customers have U.S. ECI?
Possibly, if the activities rise to the level of a U.S. trade or business. Mere solicitation and delivery from outside the U.S. generally does not create ECI, but maintaining inventory, a warehouse, or employees in the U.S. can.
What if the foreign corporation received only interest from a U.S. bank account?
Portfolio interest (from certain U.S. bonds, not bank deposits) is exempt from U.S. withholding. Regular bank deposit interest is also generally exempt. Dividends from U.S. corporations are subject to withholding. The 1120-F obligation depends on whether the income is FDAP subject to withholding.
Does the foreign corporation need a U.S. EIN?
Yes. A foreign corporation filing Form 1120-F must have a U.S. EIN, obtained via Form SS-4 with a 'foreign' responsible party.
Can a foreign corporation use a fiscal year for U.S. tax purposes?
Generally, a foreign corporation must use the same tax year for U.S. purposes as its home country unless it elects otherwise.
What is the FIRPTA impact on a foreign corporation selling U.S. real estate?
Gain from selling U.S. real property interests (USRPIs) is treated as ECI and reported on Form 1120-F. The buyer is required to withhold 35% (for corporations) under FIRPTA.
Written by
Ankit Sarawagi, CPA, CA, MBA
Ankit leads the finance team at Profitjets, where he has worked with 500+ businesses across the US on bookkeeping, tax and CFO-level strategy. He writes about the habits that keep small business books accurate all year. Connect on LinkedIn
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