A U.S. citizen can sue a non-U.S. citizen in court, and federal courts are built to handle exactly this kind of case. The main federal route is called diversity jurisdiction: it covers civil disputes between a citizen of a U.S. state and a citizen or subject of a foreign country when more than $75,000 is at stake.1Office of the Law Revision Counsel. 28 USC 1332 – Diversity of Citizenship; Amount in Controversy; Costs Getting to a courtroom is the easy part. Serving the defendant abroad, deciding whose law applies, and collecting on any judgment are where these cases become genuinely different from a domestic lawsuit.
When a Federal Court Can Hear the Case
Two things have to be true before a federal court will take your case: it needs authority over the subject matter, and it needs authority over the specific defendant you’re suing.
Subject matter jurisdiction under the diversity statute requires both diverse citizenship and more than $75,000 in controversy. One important limit: if the foreign defendant is a lawful permanent resident who is domiciled in the same state as you, diversity doesn’t apply. In that situation you’d need to file in state court or find a different federal hook, such as a claim arising under a federal statute.1Office of the Law Revision Counsel. 28 USC 1332 – Diversity of Citizenship; Amount in Controversy; Costs
Whether the Court Has Power Over That Defendant
Subject matter jurisdiction only gets you started. The court also needs personal jurisdiction over the foreign party, which turns on whether that party has meaningful ties to the United States. The Supreme Court’s decision in International Shoe Co. v. Washington set the modern test: a court can exercise jurisdiction over an out-of-state defendant with “minimum contacts” to the forum, so long as the suit doesn’t offend basic fairness.2Justia. International Shoe Co. v. Washington, 326 U.S. 310
In practice, courts look at whether the foreign defendant did business in the United States, signed a contract with a U.S. party, committed a wrongful act here, or maintained an ongoing relationship with people or entities in the forum state. A foreign company selling products nationwide through American distributors is much easier to bring into court than one that made a single sale years ago. Courts also distinguish between general jurisdiction, where the contacts are so continuous and systematic the defendant can be sued in that forum for anything, and specific jurisdiction, where the lawsuit arises directly out of the defendant’s contacts with the forum.
Suing a Foreign Government or State-Owned Company
If the non-U.S. party you want to sue is a foreign government, or a company owned by one, the analysis shifts. Under the Foreign Sovereign Immunities Act, foreign states are generally immune from suit in U.S. courts.3Office of the Law Revision Counsel. 28 USC 1602 – Findings and Declaration of Purpose That immunity has exceptions, though, and the most common one covers commercial activity: a foreign state loses its immunity when the case is based on commercial activity in the United States, an act performed here in connection with commercial activity abroad, or an act abroad that causes a direct effect here.4Office of the Law Revision Counsel. 28 USC 1605 – General Exceptions to the Jurisdictional Immunity of a Foreign State
Other exceptions apply when the foreign state waives immunity, when the claim involves property taken in violation of international law, when the suit involves U.S. real estate, or when the claim is for personal injury or death caused by a foreign official’s wrongful act on U.S. soil.4Office of the Law Revision Counsel. 28 USC 1605 – General Exceptions to the Jurisdictional Immunity of a Foreign State Federal district courts hear these cases without any minimum dollar amount, and personal jurisdiction exists automatically once service is properly made.5Office of the Law Revision Counsel. 28 U.S. Code 1330 – Actions Against Foreign States
A related doctrine can limit what the court will actually do once the case is underway. In Banco Nacional de Cuba v. Sabbatino, the Supreme Court held that U.S. courts will not examine the validity of a foreign government’s official acts within its own territory, even when those acts appear to violate international law. The Court called Cuba’s seizure of property “offensive to the public policy” of the United States but still applied the act of state doctrine.6Justia. Banco Nacional de Cuba v. Sabbatino, 376 U.S. 398 The doctrine doesn’t bar the lawsuit itself, but it can stop a court from second-guessing the foreign government’s actions as part of your case.
Even a Proper Forum Can Be Challenged
After you file, the defendant can move to dismiss under forum non conveniens, arguing that a court in another country would be a more appropriate place to litigate. Courts weigh private factors like where the evidence and witnesses are located alongside public factors like which country has a stronger interest in resolving the dispute. In Piper Aircraft Co. v. Reyno, the Supreme Court endorsed this balancing and dismissed a case in favor of a Scottish forum where most of the evidence sat.7Justia. Piper Aircraft Co. v. Reyno, 454 U.S. 235 A U.S. plaintiff’s choice of forum gets some deference, but that deference thins when the case has weak ties to the United States and strong ties elsewhere.
Getting the Papers to Your Defendant
Serving a foreign defendant is where these cases get logistically difficult. You can’t just hire a local process server to knock on a door in Tokyo or São Paulo. Federal Rule of Civil Procedure 4(f) sets the framework for serving individuals outside the United States.8Legal Information Institute. Federal Rules of Civil Procedure, Rule 4 – Summons
The Hague Service Convention
The main route is the Hague Service Convention, which more than 80 countries have joined. Each member country designates a Central Authority that receives requests from foreign litigants and arranges local delivery under its own procedures.9Hague Conference on Private International Law. Convention on the Service Abroad of Judicial and Extrajudicial Documents in Civil or Commercial Matters Simple in concept, slow in practice. A quick case takes a few weeks; typical cases run several months; in countries with heavy translation requirements or overloaded bureaucracies, service can take a year or more.
Following the Convention correctly is not optional. In Volkswagenwerk Aktiengesellschaft v. Schlunk, the Supreme Court held that the Convention applies whenever the forum state’s law requires documents to be transmitted abroad as a necessary part of service.10Justia. Volkswagenwerk Aktiengesellschaft v. Schlunk, 486 U.S. 694 A judgment obtained without proper service can be thrown out.
Alternative Methods When the Convention Doesn’t Fit
Rule 4(f) offers alternatives when the Convention doesn’t cover the situation or isn’t producing results. If the defendant lives in a non-Convention country, you can serve using methods prescribed by that country’s own law, through a letter rogatory (a formal request from the U.S. court to a foreign court for assistance), or by personal delivery or certified mail unless the foreign country prohibits it.8Legal Information Institute. Federal Rules of Civil Procedure, Rule 4 – Summons
Rule 4(f)(3) gives courts broader latitude to authorize any method of service not prohibited by an applicable international agreement. Federal courts have used this to approve service by email, social media, and other electronic means when traditional methods have failed or are impractical. This isn’t a last resort. Courts treat it as an independent option, provided the method is reasonably likely to give the defendant actual notice.8Legal Information Institute. Federal Rules of Civil Procedure, Rule 4 – Summons For a defendant who operates online or whose physical address is unknown, that provision can be the difference between a case that moves and one that stalls indefinitely.
Whose Law the Court Will Apply
Filing in a U.S. court doesn’t automatically mean American law governs the substance of your dispute. Courts go through a choice of law analysis to decide which country’s rules apply to each issue.
In contract cases, the answer is often written into the contract. Most international agreements include a clause specifying which jurisdiction’s law controls, and courts generally honor those clauses. Without one, courts look at where the contract was negotiated, signed, and performed to identify the jurisdiction with the closest relationship to the deal.
Tort cases work differently. The widely adopted approach from the Restatement (Second) of Conflict of Laws directs courts to apply the law of the jurisdiction with the most significant relationship to the dispute. For a personal injury claim, that’s usually where the injury happened, unless another jurisdiction has stronger ties to the parties and the conduct at issue.
Public policy is a backstop. A U.S. court can refuse to apply foreign law that would violate fundamental American legal principles, but the exception is narrow. Courts don’t reject foreign law just because it differs from U.S. law or produces a less favorable outcome. The foreign rule has to clash with a core principle of justice or fairness.
Which body of law applies can decide the case. It affects available damages, filing deadlines, the standard of proof, and which defenses exist. A claim that looks strong under American law may be weak or nonexistent under the law of the country where the harm occurred.
Locking Down Assets Before Judgment
A verdict is worth nothing if the defendant has moved the money before you can collect. Foreign defendants can shift assets across borders with relative ease, which is why acting early matters. Federal Rule of Civil Procedure 64 lets courts order seizure of property at the start of a case using whatever remedies the forum state makes available, including attachment, garnishment, and sequestration.11Legal Information Institute. Federal Rules of Civil Procedure, Rule 64 – Seizing a Person or Property
Pre-judgment attachment of a foreign defendant’s U.S.-based bank accounts, real estate, or business interests can freeze those assets while the case proceeds. You generally need to show a real risk the defendant will dissipate or hide assets without a court order. The specifics vary with the state law applied in your federal district, so the requirements in New York’s federal courts differ from those in California’s.
Actually Collecting Across Borders
Winning a U.S. judgment is often only halfway to recovering money from a foreign defendant. If the defendant has assets in the United States, you can enforce the judgment domestically through standard collection procedures. The harder scenario is when you need a foreign court to recognize and enforce your American judgment.
The United States has no treaty with any country specifically governing mutual recognition of court judgments. That gap surprises many litigants. Enforcement instead depends on the internal law of the country you’re asking to honor the judgment, and countries vary widely in how receptive they are. Foreign courts typically look at whether the U.S. court had jurisdiction, whether the procedures were fair, whether the defendant received adequate notice, whether the judgment was obtained by fraud, and whether the underlying claim conflicts with local public policy.
Enforcement difficulty should shape your strategy from the beginning. If the defendant’s assets are concentrated in a country that routinely refuses to enforce American judgments, even a large verdict may be uncollectable. In some cases it makes more sense to sue in the country where the assets actually sit, even though that means litigating in a foreign legal system.
The Arbitration Alternative
Many cross-border commercial contracts require disputes to be resolved through arbitration rather than court. If your agreement includes an arbitration clause, a lawsuit may not be available. But arbitration has a real enforcement advantage: the Convention on the Recognition and Enforcement of Foreign Arbitral Awards, known as the New York Convention, obligates more than 170 member countries to recognize and enforce arbitration awards from other member states.12UNCITRAL. Convention on the Recognition and Enforcement of Foreign Arbitral Awards
That treaty network makes arbitration awards far easier to enforce internationally than court judgments. Where a foreign court might ignore a U.S. judgment, an arbitration award rendered in the U.S. can be taken to nearly any commercial hub in the world and enforced. When collecting money across borders is the central concern, arbitration is often the more practical path. Even without a pre-existing clause, both parties can agree to arbitrate after a dispute arises.
What the Process Costs and How Long It Takes
International litigation is expensive compared to domestic cases. Beyond ordinary attorney fees, expect costs for translating documents, hiring foreign counsel to coordinate service or enforcement, international travel for depositions or hearings, and fees charged by central authorities for processing service requests. Federal court filing fees for a civil case typically run from roughly $50 to over $400 depending on the court, but those fees are a small share of the total.
Timelines are harder to predict. Hague Convention service alone commonly takes two to six months, and delays of a year or more aren’t unusual in some countries. Add discovery disputes over foreign evidence, likely challenges to jurisdiction and venue, and the enforcement process after judgment, and a straightforward international case can easily run three to five years. Complex cases take longer. Budgeting for that upfront prevents the kind of mid-case surprises that force plaintiffs to abandon otherwise winnable claims.