If you’re a foreign shareholder in a US C corporation, you’re looking at a layered tax picture: the company pays 21% federal tax on its profits, dividends paid to you face up to 30% US withholding (often lower under a treaty), gains on selling your stock are usually not taxed by the US, and your shares sit inside the US estate tax net with only a $60,000 exemption. Each of those layers has conditions worth understanding before you buy in.
The Two Layers of Tax on Profits
A US C-Corporation pays federal income tax on its worldwide net income at a flat 21%, no matter who owns it.1Office of the Law Revision Counsel. 26 USC 11 – Tax Imposed Foreign ownership doesn’t change that. The corporation files Form 1120 like any other domestic corporation.2Internal Revenue Service. About Form 1120, U.S. Corporation Income Tax Return
The second layer hits when profits come out to you. The tax treatment of a distribution depends on the corporation’s earnings and profits (E&P). Distributions come out of E&P first and are treated as dividends. Any amount beyond E&P reduces your stock basis, and anything beyond basis is taxed as a capital gain.3Office of the Law Revision Counsel. 26 USC 301 – Distributions of Property
The dividend portion faces a flat 30% withholding tax on the gross amount paid.4Internal Revenue Service. The Taxation of Capital Gains of Nonresident Students, Scholars and Employees of Foreign Governments The 30% rate applies unless you qualify for a reduced rate under an income tax treaty between your country of residence and the United States. Treaty rates on dividends commonly fall to 15%, 10%, or even 5%, depending on the treaty and your ownership stake.
Claiming a Treaty Rate
To get the reduced rate, you have to give the corporation a properly completed Form W-8BEN (if you’re an individual) or Form W-8BEN-E (if you’re an entity) before the dividend is paid.5Internal Revenue Service. About Form W-8 BEN-E, Certificate of Status of Beneficial Owner for United States Tax Withholding and Reporting (Entities) Without a valid W-8 on file, the corporation must default to 30%. Most treaties also include a Limitation on Benefits clause, which stops investors from routing ownership through a treaty country solely to capture the lower rate.
The corporation, acting as withholding agent, reports the amounts withheld on Form 1042 and issues you a Form 1042-S showing the income paid and tax withheld.6Internal Revenue Service. About Form 1042, Annual Withholding Tax Return for U.S. Source Income of Foreign Persons You use the 1042-S to claim credit for the US tax already collected. Both forms are due by March 15 of the year following the payments.7Internal Revenue Service. Instructions for Form 1042-S (2026)
Do You Have to File a US Return?
Dividends fall into the passive category of US-source income (fixed or determinable annual or periodical income). If dividends are all you receive, the withholding at source usually satisfies your US tax liability, and you don’t file a US return. That changes if you have Effectively Connected Income, which is income tied to an actual US trade or business and taxed at graduated rates. In that case you’d file Form 1040-NR.
Selling Your C-Corp Stock
The default rule is generous. The United States generally doesn’t tax capital gains earned by a nonresident alien on the sale of US corporate stock. The exemption holds as long as you weren’t physically present in the United States for 183 days or more during the tax year of the sale. If you cross that threshold, you owe a flat 30% tax on net US-source capital gains for that year.8eCFR. 26 CFR 1.871-7 – Taxation of Nonresident Alien Individuals
The FIRPTA Exception
The Foreign Investment in Real Property Tax Act is the major exception. Congress didn’t want foreign investors sidestepping US tax on real estate gains just by holding property inside a corporation and selling the shares.
FIRPTA applies when the C-Corp qualifies as a US Real Property Holding Corporation. That means the fair market value of its US real property interests equals or exceeds 50% of the combined fair market value of its US real property, foreign real property, and other business assets.9Office of the Law Revision Counsel. 26 USC 897 – Disposition of Investment in United States Real Property US real property interests include land, buildings, mines, wells, and associated natural resources located in the United States.
If the corporation clears the 50% threshold, your gain on the stock sale is treated as Effectively Connected Income and taxed at graduated US rates. You file Form 1040-NR to report it. The buyer must withhold 15% of the total amount realized and remit it to the IRS using Forms 8288 and 8288-A.10Office of the Law Revision Counsel. 26 USC 1445 – Withholding of Tax on Dispositions of United States Real Property Interests A buyer who fails to withhold becomes personally liable for the full amount.11Internal Revenue Service. 9Office of the Law Revision Counsel. 26 USC 897 – Disposition of Investment in United States Real Property For small positions in publicly listed US companies, even real-estate-heavy ones, FIRPTA effectively drops out.
The Estate Tax Problem
This is what catches many foreign investors off guard. Stock in a US corporation is treated as property situated in the United States for estate tax purposes, regardless of where you live.12Office of the Law Revision Counsel. 26 USC 2104 – Property Within the United States If you die while holding C-Corp shares, those shares are part of your US-taxable estate.
The rate schedule for nonresident aliens is the same graduated structure that applies to US citizens, topping out at 40% for estates above roughly $1 million. The exemption is where things diverge sharply. US citizens and residents currently benefit from an exemption above $13 million. A nonresident alien’s estate gets only a $13,000 unified credit, which shelters roughly $60,000 of US-situs assets from tax.13Internal Revenue Service. Estate Tax for Nonresidents Not Citizens of the United States The $60,000 figure is not indexed for inflation and has held steady for decades.
The practical impact is stark. A foreign investor who dies holding $2 million in C-Corp stock could leave their heirs facing an estate tax bill approaching $700,000 or more, with almost no exemption to soften it. Some estate tax treaties provide a higher exemption or a proportional credit, but these treaties are relatively few. If you hold significant C-Corp stock, estate planning belongs at the front of the process. Holding shares through a foreign corporation or trust can reduce exposure, though each structure brings its own tax and reporting trade-offs.14Office of the Law Revision Counsel. 26 USC 2101 – Tax Imposed
If You Own 25% or More: Form 5472
Owning a meaningful stake pulls the corporation into an information reporting regime that will pull you in too. When a single foreign person holds at least 25% of the corporation’s total voting power or total stock value at any point during the tax year, the corporation must file Form 5472 for each reportable transaction with you and other related foreign parties.15Office of the Law Revision Counsel. 26 USC 6038A – Information With Respect to Certain Foreign-Owned Corporations Reportable transactions include sales, purchases, service fees, rents, royalties, loans, and similar dealings between you and the company.16Internal Revenue Service. About Form 5472
The IRS uses Form 5472 to enforce transfer pricing rules, meaning the prices charged between the corporation and you should reflect what unrelated parties would charge at arm’s length. Documentation supporting comparability matters, because foreign-owned companies are audited aggressively in this area.
Penalties are steep: $25,000 for each year the corporation fails to file or maintain required records, with an additional $25,000 for every 30-day period (or fraction) that passes after a 90-day grace period following an IRS notice.15Office of the Law Revision Counsel. 26 USC 6038A – Information With Respect to Certain Foreign-Owned Corporations The filing requirement applies even if the corporation reports no taxable income or runs a loss; it’s triggered purely by ownership and the presence of reportable transactions.
Lending Money to the Company
Foreign shareholders often prefer to fund US operations through loans rather than additional equity, because interest is deductible against corporate income while dividends aren’t. Congress has placed guardrails on the strategy, sometimes called earnings stripping.
Under Section 163(j), a C-Corp can generally deduct business interest expense only up to 30% of adjusted taxable income, plus any business interest income. For tax years beginning after December 31, 2024, the One, Big, Beautiful Bill Act permanently restored the more favorable EBITDA-based calculation, so the corporation adds back depreciation, amortization, and depletion when computing the limit.17Internal Revenue Service. Questions and Answers About the Limitation on the Deduction for Business Interest Expense Interest that exceeds the cap carries forward to future years.
Section 163(j) isn’t the only concern. The IRS scrutinizes related-party loans between a foreign parent or shareholder and a US corporation. If the loan terms don’t match what an unrelated lender would offer, such as an inflated interest rate, no real repayment schedule, or an overleveraged balance sheet, the IRS may recharacterize part or all of the debt as equity. That reclassification turns deductible interest into nondeductible dividend distributions, and it can trigger back withholding on the reclassified amounts.