A company formed outside the United States that wants to do business here faces two separate compliance layers: registration with each state where it operates, and federal obligations covering income tax, withholding, information reporting, and, in some cases, beneficial ownership disclosure or national security review. Meeting one layer does not satisfy the other, and the penalties for skipping either are real. This guide walks through the foreign entity US registration and tax rules you need to work through before and during operations.
Under US law, an entity is “foreign” based on where it was created, not on who owns it or where its customers live. Any corporation, LLC, partnership, or trust organized under the laws of another country is a foreign entity for both federal tax and state registration purposes. (US states also use “foreign” to describe entities formed in another US state, but that is a different concept from what this article covers.)
State Registration Through Foreign Qualification
Before conducting ongoing business in a US state, a foreign entity generally must complete foreign qualification through that state’s Secretary of State or equivalent office. The filing produces what most states call a Certificate of Authority, which grants permission to operate.1U.S. Small Business Administration. Expand to New Locations You need to qualify in every state where your activities cross the threshold for “transacting business.”
What Counts as Transacting Business
States look at practical factors. The common triggers include maintaining a physical office or warehouse, employing workers in the state, holding regular in-person meetings with clients there, or earning a significant share of revenue from state-based activities.2U.S. Small Business Administration. Register Your Business If any of these describe what you’re doing, qualification is almost certainly required.
Nearly every state also lists activities that do not count. Maintaining a bank account, owning real property without operating a business on it, defending a lawsuit, collecting debts, and completing an isolated one-off transaction generally fall below the threshold. Interstate commerce by itself does not require qualification, because requiring it would run into Commerce Clause problems. The exact wording of these carve-outs varies by state.
Documents and Registered Agent
The Certificate of Authority application typically requires a certified copy of the entity’s formation documents from its home country and a Certificate of Good Standing (or equivalent) from that jurisdiction.1U.S. Small Business Administration. Expand to New Locations The filing must identify the entity’s purpose, its principal office address, and its jurisdiction of formation.
Every state also requires you to designate a registered agent with a physical address in that state to accept legal documents and government correspondence.2U.S. Small Business Administration. Register Your Business Foreign entities without a US presence generally hire a commercial registered agent service, typically $35 to $350 per year depending on the state and provider. State filing fees for the Certificate itself vary.
What Happens if You Skip Qualification
The most damaging consequence is not the fine. In most states, an unqualified foreign entity cannot file a lawsuit or enforce a contract in that state’s courts until it obtains a Certificate of Authority. You can still be sued, and you must defend, but you cannot initiate. States also typically require the unqualified entity to pay all back fees and taxes it would have owed if it had registered on time, plus civil penalties. Retroactive compliance costs far more than registering upfront.
Getting an EIN
Every foreign entity engaged in a US trade or business needs an Employer Identification Number from the IRS before it can file tax returns, open bank accounts, or hire employees. The route for foreign entities differs from the standard domestic online application.
A foreign entity without a legal residence, principal office, or place of business in the US applies by calling the IRS at 267-941-1099 (not toll-free) during business hours, faxing a completed Form SS-4 to 304-707-9471 from outside the US, or mailing Form SS-4 to the IRS EIN International Operation office in Cincinnati, Ohio.3Internal Revenue Service. Instructions for Form SS-4 Phone applications produce an EIN immediately. Fax typically takes a few business days. Mail takes four to five weeks, so build that in if you have a filing deadline coming up.
Federal Income Tax on Effectively Connected Income
The core federal tax concept for foreign entities operating in the US is effectively connected income, or ECI: income from activities tied to a trade or business conducted within the United States. A foreign corporation pays tax on its ECI at the same graduated corporate rates as a domestic corporation and can deduct expenses directly connected to earning that income.4Office of the Law Revision Counsel. 26 USC 882 – Tax on Income of Foreign Corporations Connected With United States Business For nonresident alien individuals, ECI is taxed at the regular individual graduated rates.5Office of the Law Revision Counsel. 26 USC 871 – Tax on Nonresident Alien Individuals
Form 1120-F
A foreign corporation must file Form 1120-F, the US income tax return for foreign corporations, if during the tax year it was engaged in a US trade or business, had ECI, or had US-source income where withholding did not fully cover the liability. Filing is required even when no tax is owed. A foreign corporation that wants to claim deductions or credits against US income has to file this return to preserve those claims. Entities relying on a tax treaty to reduce US tax must also file Form 1120-F along with Form 8833 disclosing the treaty position.6Internal Revenue Service. Instructions for Form 1120-F
Branch Profits Tax
Foreign corporations face an additional tax that domestic corporations do not. On top of the regular income tax on ECI, a foreign corporation owes a branch profits tax equal to 30% of its “dividend equivalent amount,” which roughly represents after-tax earnings that have been or could be repatriated to the foreign parent.7Office of the Law Revision Counsel. 26 USC 884 – Branch Profits Tax The rationale: a US subsidiary of a foreign parent would face withholding when it paid dividends to the parent, and without the branch profits tax, a foreign corporation could sidestep that layer by operating as a US branch instead of a subsidiary. Income tax treaties often reduce or eliminate the branch profits tax for entities that qualify as residents of the treaty country.8eCFR. 26 CFR 1.884-1 – Branch Profits Tax
Withholding on Passive US-Source Income
Not all US-source income comes from operating a business. Dividends, certain interest payments, royalties, licensing fees, and similar periodic payments to foreign entities are classified as FDAP (fixed, determinable, annual, or periodical) income. The default withholding rate on FDAP paid to a foreign corporation is 30%, deducted at the source before the payment reaches you.9Office of the Law Revision Counsel. 26 USC 1442 – Withholding of Tax on Foreign Corporations The same 30% applies to payments to nonresident alien individuals.10Office of the Law Revision Counsel. 26 USC 1441 – Withholding of Tax on Nonresident Aliens
US tax treaties with many countries reduce or eliminate this rate for specific income types. To claim a reduced rate, you have to file the appropriate W-8 form with the party making the payment before the payment goes out. Entities use Form W-8BEN-E; individuals use Form W-8BEN.11Internal Revenue Service. Claiming Tax Treaty Benefits The form requires you to certify that you are a resident of the treaty country, are the beneficial owner of the income, and meet any limitation-on-benefits provision. Without a valid W-8 on file, the payor must withhold the full 30%.
Information Reporting
Form 5472
Form 5472 is one of the most consequential reporting forms for foreign-owned entities in the US, and the penalty for getting it wrong is severe. The form must be filed by any 25% foreign-owned US corporation (including a foreign-owned disregarded entity), or any foreign corporation engaged in a US trade or business, that has reportable transactions with a related party during the tax year.12Internal Revenue Service. Instructions for Form 5472
Reportable transactions cover a wide range of dealings between the US entity and its foreign related parties: sales, rents, royalties, loans, service fees, and more. The penalty for failing to file on time starts at $25,000 per form. If the IRS notifies you and you still don’t file within 90 days, another $25,000 accrues for each 30-day period the failure continues, per related party.12Internal Revenue Service. Instructions for Form 5472 The same penalties apply for failing to maintain the required records. The IRS shows very little flexibility here, and totals escalate fast for entities with multiple foreign related parties.
Transfer Pricing Under Section 482
When a foreign entity does business with a related US entity, the prices between them must reflect what unrelated parties would agree to in the same circumstances. The IRS has authority under Section 482 to adjust income, deductions, and credits between commonly controlled entities to prevent tax avoidance and ensure each entity’s reported income matches economic reality.13Internal Revenue Service. Transfer Pricing
If intercompany prices deviate significantly from arm’s-length standards, penalties escalate with the size of the discrepancy. A 20% penalty applies when the transfer price claimed on a return is 200% or more (or 50% or less) of the correct price, or when the total net adjustment exceeds the lesser of $5 million or 10% of gross receipts. A 40% penalty applies for more extreme distortions, where the price is 400% or more (or 25% or less) of the correct amount, or the net adjustment exceeds the lesser of $20 million or 20% of gross receipts. Contemporaneous transfer pricing documentation is the primary defense, because it shows the entity applied a reasonable method before filing.
Beneficial Ownership Reporting to FinCEN
The Corporate Transparency Act created a federal beneficial ownership reporting requirement, and after a March 2025 interim final rule, that requirement now falls specifically on foreign entities. FinCEN narrowed the definition of “reporting company” to include only entities formed under the law of a foreign country that have registered to do business in a US state or tribal jurisdiction.14Financial Crimes Enforcement Network. Beneficial Ownership Information Reporting Domestic US companies and US persons were removed from the reporting requirements entirely.
Foreign entities that qualify as reporting companies and don’t fall under one of the statutory exemptions must file a beneficial ownership information report with FinCEN. These entities are not required to report US persons as beneficial owners. Entities registered to do business in the US before March 26, 2025, had to file their initial report by April 25, 2025. Those registering on or after March 26, 2025, have 30 calendar days after receiving notice that their registration is effective.14Financial Crimes Enforcement Network. Beneficial Ownership Information Reporting Because these deadlines come from an interim final rule, check FinCEN for changes when a final rule is published.
When National Security and Political Rules Apply
Two federal regimes sit outside the tax and registration path but catch some foreign entities anyway.
The Foreign Agents Registration Act requires anyone acting as an agent of a foreign government, political party, or foreign entity to register with the Department of Justice when they engage in political activities, public relations, fundraising, or information campaigns in the United States on that principal’s behalf.15United States Department of Justice. Foreign Agents Registration Act Registration means ongoing public disclosure of the relationship, activities, and financial flows. Willful violations, including materially false registration statements, can result in fines up to $250,000, imprisonment up to five years, or both. Lesser violations involving labeling failures, inadequate disclosures, or prohibited fee arrangements carry fines up to $5,000 and up to six months imprisonment.16United States Department of Justice. FARA Enforcement
The Committee on Foreign Investment in the United States (CFIUS) reviews transactions that could give a foreign person control over a US business, looking for national security risks. CFIUS also reviews certain non-controlling investments in US businesses that handle critical technologies, critical infrastructure, or sensitive personal data.17U.S. Department of the Treasury. CFIUS Overview Many CFIUS filings are voluntary, but declarations are mandatory for certain critical-technology transactions, particularly where the foreign acquirer is connected to a foreign government with a substantial interest in the deal.18U.S. Department of the Treasury. CFIUS Frequently Asked Questions If CFIUS identifies risks it cannot address through other laws, it can negotiate mitigation agreements, impose conditions, or refer the matter to the President, who has authority to block or unwind completed deals.