International subpoenas do not exist as a single instrument the way a domestic subpoena does. A Rule 45 subpoena issued by a U.S. court has no force outside the United States, so compelling testimony or documents from someone abroad means using one of several substitute mechanisms: a Letter of Request under the Hague Evidence Convention, a letter rogatory through diplomatic channels, a federal subpoena directed at a U.S. national overseas under 28 U.S.C. § 1783, or direct discovery against a foreign party already subject to the court’s jurisdiction. Which path fits depends on the country, the citizenship of the witness, and whether that witness is already a party to your case.
Why a U.S. Subpoena Stops at the Border
Federal Rule of Civil Procedure 45 allows service of a subpoena anywhere within the United States, and anywhere only within the United States.1Legal Information Institute. Federal Rules of Civil Procedure Rule 45 – Subpoena You cannot serve a standard Rule 45 subpoena on a foreign national or foreign entity sitting outside the country. For U.S. nationals abroad, Rule 45(b)(3) routes you to 28 U.S.C. § 1783. For everyone else, you are in treaty or diplomatic territory.
There is one important workaround that avoids the international apparatus entirely. When a U.S. company has possession, custody, or control over records held by a foreign affiliate, a U.S. court can order the domestic entity to produce those foreign-held documents. Courts examine the real relationship between the entities: whether the U.S. company has the legal right or the practical ability to obtain the records from its foreign counterpart. The foreign affiliate itself is not compelled; the obligation falls on the U.S. entity. The analysis is fact-intensive and heavily contested, which is why opposing parties fight so hard over whether “control” actually exists.
The Hague Evidence Convention Route
The Hague Convention on the Taking of Evidence Abroad in Civil or Commercial Matters is the main treaty framework. Sixty-nine countries are parties, including most of Europe, China, Australia, and much of Latin America.2HCCH. Status Table – Convention of 18 March 1970 on the Taking of Evidence Abroad When evidence sits in a member country, the standard move is a Letter of Request issued by the U.S. court where your case is pending and sent to the Central Authority designated by the foreign nation.
A Letter of Request has to carry enough detail for the foreign authority to act. That means identifying the parties and their addresses, describing the nature of the case, specifying the evidence sought, and naming any witnesses. Document requests need descriptions precise enough for the foreign authority to locate the records. Testimony requests need the witness’s contact information and a list of specific questions.3U.S. Department of Justice. Evidence Requests If you want a deposition rather than written answers to interrogatories, say so explicitly. Written interrogatories are the default.
Once the U.S. court issues the Letter, the foreign Central Authority reviews it for Convention and local-law compliance, then executes it through its own domestic procedures. The U.S. Department of Justice acts as the U.S. Central Authority for inbound requests coming from foreign courts, but it does not process or transmit outbound requests on behalf of private U.S. litigants.3U.S. Department of Justice. Evidence Requests If you are seeking evidence abroad, your Letter goes directly to the foreign Central Authority through channels your attorney arranges.
The Article 23 Problem
This is where most requests run aground. Many signatory countries have declared under Article 23 that they will not execute Letters of Request issued for pre-trial document discovery as practiced in common law systems.4U.S. Department of Justice. Hague Evidence Convention Text The broad, exploratory discovery that U.S. litigation treats as routine has no equivalent in most civil-law systems. A request that looks like a fishing expedition will almost certainly be refused. Draft narrowly, tie each requested item to a specific fact in dispute, and name specific documents and witnesses rather than categories.
Voluntary Testimony Through Consular Officers and Commissioners
The Convention also allows evidence to be taken voluntarily. Under Articles 15 through 17, a consular agent can take uncompelled testimony from nationals of the country they represent, and with host-country permission, from host-country nationals or third-country nationals.4U.S. Department of Justice. Hague Evidence Convention Text Commissioners appointed by the court can play a similar role. When a witness is willing to cooperate, these channels often move faster than a Letter of Request, though whether prior permission is needed depends entirely on the host country.
Video-Link Testimony
Taking testimony by video link under the Convention has become common, but the rules are country-specific. The requesting court still uses either the Letter of Request process or the diplomatic/commissioner channels, specifying that video-link testimony is sought. Some countries require a local judge to be present during the examination. Most expect proposed dates and times, technical specifications for the connection, an expected session length, and language or interpretation arrangements. Confirm the specific requirements for the host country before building a Letter of Request around a video deposition.
The Convention Is Not Mandatory
A point that catches many litigators off guard: the Hague Evidence Convention is not the exclusive route to foreign evidence, even for signatory countries. In Societe Nationale Industrielle Aerospatiale v. U.S. District Court (1987), the Supreme Court held that the Convention sets up optional procedures that supplement, rather than replace, the Federal Rules of Civil Procedure.5Justia US Supreme Court. Societe Nationale v. District Court, 482 U.S. 522 (1987) The Court pointed to the Convention’s own permissive language about facilitating discovery.
What that means in practice: if a U.S. court has personal jurisdiction over a foreign party, whether because the party does business in the United States or has otherwise submitted to jurisdiction, the court can order that party to produce foreign-located evidence under the Federal Rules without going through the Convention at all. Courts weigh the burdens case by case, looking at the importance of the evidence, how specifically the request is tailored, and whether the foreign country has a strong sovereign interest in preventing disclosure. The Convention is one tool, not the required gateway.
Letters Rogatory When There Is No Treaty
If the country holding the evidence is not a Hague Convention party, or if Convention channels prove impractical, the fallback is a letter rogatory. This is a formal request from a U.S. court to a foreign court asking it to perform a judicial act, usually taking testimony or ordering document production. The mechanism rests on international comity, not treaty obligation, which means the foreign court assists because it chooses to.
Under 28 U.S.C. § 1781, the State Department has authority to transmit letters rogatory from U.S. courts to foreign tribunals through diplomatic channels.6Office of the Law Revision Counsel. 28 USC 1781 – Transmittal of Letter Rogatory or Request Direct court-to-court transmission is also permitted, but the diplomatic route is the norm. Expect the full process to take a year or more.7U.S. Department of State. Preparation of Letters Rogatory The foreign court decides at its discretion whether to execute the request and applies its own procedural and evidentiary rules, so the result can look very different from what U.S. litigators expect. Reserve letters rogatory for situations where no better mechanism exists.
Reaching a U.S. National or Resident Abroad
There is one setting where a U.S. court can issue something close to a traditional subpoena across borders. Under 28 U.S.C. § 1783, a federal court can order a subpoena directed at a U.S. national or permanent resident abroad, compelling them to appear as a witness or to produce specified documents.8Office of the Law Revision Counsel. 28 USC 1783 – Subpoena of Person in Foreign Country The threshold is high: the court must find that the testimony or documents are necessary in the interest of justice, and in civil cases, that no other way exists to obtain the evidence in admissible form.
The subpoena has to specify a time and place for appearance or production, and the person serving it must tender estimated travel and attendance expenses as the court sets them. Service follows the Federal Rules for serving process on a person in a foreign country. If the recipient ignores it, 28 U.S.C. § 1784 authorizes contempt sanctions including fines and seizure of U.S. property. This mechanism is limited to U.S. nationals and residents. It cannot reach foreign citizens abroad.
The Other Direction: Foreign Litigants Seeking Evidence in the U.S.
The process also runs the other way. Under 28 U.S.C. § 1782, a foreign tribunal or any “interested person” (typically a party to foreign litigation) can petition a U.S. district court to order a person residing or found in the district to give testimony or produce documents for use in a foreign proceeding.9Office of the Law Revision Counsel. 28 USC 1782 – Assistance to Foreign and International Tribunals The statute hands foreign litigants access to the broad discovery tools of U.S. federal courts, and the evidence does not need to be discoverable under the foreign court’s own rules.
A court considering a § 1782 application checks three threshold requirements: the request must come from an interested person or a foreign tribunal, the evidence must be for use in a foreign or international proceeding, and the target must reside or be found in the district. If those are satisfied, the court exercises discretion under the factors set out by the Supreme Court in Intel Corp. v. Advanced Micro Devices (2004).10Legal Information Institute. Intel Corp. v. Advanced Micro Devices, Inc. Those factors ask whether the evidence holder is already a participant in the foreign proceeding (in which case U.S. assistance is less necessary), whether the foreign tribunal would be receptive to the evidence, whether the request appears aimed at circumventing foreign proof-gathering restrictions, and whether the request is unduly intrusive or burdensome.
Private Arbitration Does Not Count
In 2022, the Supreme Court closed a significant door. In ZF Automotive US, Inc. v. Luxshare, Ltd., the Court held unanimously that § 1782 reaches only proceedings before governmental or intergovernmental adjudicative bodies. Private commercial arbitration panels do not qualify as “foreign or international tribunals.”11Supreme Court of the United States. ZF Automotive US, Inc. v. Luxshare, Ltd., 596 U.S. 619 (2022) If your dispute is in private arbitration, § 1782 is not available. Arbitral bodies that exercise governmental authority, such as some investor-state panels, may still qualify.
Foreign Blocking Statutes and Data Privacy Laws
Even when a U.S. court has clear authority to order discovery, foreign law can create a real conflict. Some countries have enacted blocking statutes that criminalize compliance with foreign discovery orders on certain subjects. France’s blocking statute is the most well-known. In Aerospatiale, the Supreme Court noted that a foreign law prohibiting disclosure does not strip a U.S. court of the power to order a party under its jurisdiction to produce evidence.5Justia US Supreme Court. Societe Nationale v. District Court, 482 U.S. 522 (1987) Courts have also observed that these statutes are rarely enforced against parties who disclose evidence to comply with U.S. court orders, which weakens the argument that compliance creates serious legal exposure.
The EU’s General Data Protection Regulation adds another layer. When evidence includes personal data of EU residents, transferring it to the United States for litigation triggers GDPR’s Chapter V transfer rules. Article 48 states that a foreign court order alone is not a recognized basis for transferring personal data out of the EU. The producing party has to find an independent legal basis under Article 6 and satisfy the GDPR’s transfer provisions, which may include relying on the narrow derogations in Article 49. In practice, that means stripping out personal data irrelevant to the claims, anonymizing where possible, and documenting why the transfer is necessary. The tension between aggressive U.S. discovery and European privacy law is not resolving cleanly.
Practical Points That Decide Whether Any of This Works
Cross-border evidence gathering is slow, expensive, and procedurally unforgiving. A few things that experienced practitioners know:
- Start early. Hague Convention requests can take several months even in cooperative countries, and letters rogatory routinely exceed a year. Begin as soon as litigation is reasonably anticipated. Waiting until discovery deadlines are near creates problems that urgency cannot solve.
- Draft narrowly. The single biggest reason Letters of Request fail is that they read like domestic discovery. Foreign authorities are not interested in helping you explore whether relevant evidence might exist. Identify specific documents and specific witnesses, and frame questions precisely.
- Authenticate everything. Evidence obtained abroad generally needs authentication for use in U.S. proceedings. For Hague Apostille Convention countries, an apostille streamlines the process. For non-member countries, full consular authentication adds time and cost.
- Pursue parallel paths. Because the Hague Convention is not exclusive, you can sometimes pursue Convention channels and direct Federal Rules discovery at the same time when you have jurisdiction over the opposing party. Courts occasionally encourage this when the Hague process looks slow or uncertain.
- Budget for translation. Documents produced in a foreign language need certified translation. On large productions, translation costs can rival attorney fees.