Evidence in International Arbitration: The IBA Rules, Document Production, Witness Statements, and Expert Evidence

The general counsel of a Houston water-technology company opens the draft of Procedural Order No. 1 in her ICC arbitration against a German supplier and reads it twice. There is a deadline for "Requests to Produce," limited to "narrow and specific categories." There is a deadline for witness statements, which will "stand as the evidence-in-chief of the witness." There is a sentence saying the tribunal "may be guided by" the IBA Rules on the Taking of Evidence in International Arbitration. There is no mention of depositions, interrogatories, or requests for admission. She calls outside counsel with one question: how are we supposed to prove that they knew the membranes were defective if we cannot depose their engineers?

The answer is that she will prove it differently. International arbitration has its own law of evidence, built from a few lines of institutional rules, a widely used set of soft-law rules drafted by the International Bar Association, the procedural orders of each tribunal, and a thin layer of national law at the seat and at the place of enforcement. Lawyers trained in U.S. litigation tend to read that system as "discovery lite." It is better understood as a different theory of proof: each side proves its own case with the documents it has, a short list of documents it can persuade the tribunal to order from the other side, written testimony that its witnesses adopt, and expert reports that the tribunal will test, often by putting the experts in the same room. The lawyer who learns that theory early wins evidentiary arguments that the lawyer who fights it loses.

The short answer

• The tribunal controls the evidence. National arbitration laws and institutional rules give tribunals broad discretion over admissibility, relevance, materiality, and weight, subject to equal treatment and a fair opportunity to present one's case. The Federal Rules of Evidence, by their own terms, govern court proceedings (Fed. R. Evid. 1101), not arbitrations.
• The IBA Rules are the default vocabulary. The 2020 IBA Rules on the Taking of Evidence are adopted outright in some cases and used "as guidelines" in many more. They split the difference between common-law disclosure and civil-law practice.
• Document production is narrow by design. Under Article 3 of the IBA Rules, a request must identify specific documents or a "narrow and specific" category reasonably believed to exist, and must explain why each is relevant to the case and material to its outcome. The vehicle is a Redfern schedule. There is no general duty to produce adverse documents.
• Objections are about relevance, privilege, burden, confidentiality, and proportionality. Article 9 lists them, adds a power to exclude illegally obtained evidence, and gives tribunals a list of factors for resolving privilege conflicts between legal systems.
• The sanction is an inference, not contempt. A party that fails to produce ordered documents without a satisfactory explanation risks an adverse inference under Article 9.6 and adverse costs under Article 9.8.
• Witness statements replace direct examination. Counsel may interview and prepare witnesses, but the statement must be the witness's own account, and live testimony is mostly cross-examination.
• Experts are increasingly tested together. Party-appointed experts must be independent; tribunals may also appoint their own; and witness conferencing ("hot-tubbing") is now routine in technical cases.
• U.S. courts add less than U.S. lawyers expect. ZF Automotive US, Inc. v. Luxshare, Ltd., 596 U.S. 619 (2022), closed 28 U.S.C. § 1782 to private commercial arbitration. Arbitrator subpoenas under 9 U.S.C. § 7 reach nonparties, but most circuits allow them only for appearance at a hearing before the arbitrators.
• Evidentiary rulings rarely sink awards, but some do. Courts set aside or refuse enforcement only when a ruling denied a party a fundamentally fair hearing, as in Iran Aircraft Industries v. Avco Corp., 980 F.2d 141 (2d Cir. 1992).

Why arbitration needed its own law of evidence

Two traditions at one table

A U.S. lawyer arrives at an international arbitration with a set of instincts formed by Fed. R. Civ. P. 26: discovery of any nonprivileged matter relevant to a claim or defense and proportional to the needs of the case, depositions of any witness under Rule 30, requests for production under Rule 34, requests for admission under Rule 36, and sanctions under Rule 37. English lawyers bring a narrower but still adversarial tradition of standard disclosure and cross-examination. A lawyer from Germany, Switzerland, or France brings a different set of instincts entirely. In those systems the judge leads the inquiry, each party produces the documents it relies on, compelled production from an opponent is exceptional and limited to specifically identified documents, and lawyers in some jurisdictions have historically avoided substantive contact with fact witnesses before trial.

Put those lawyers in a room with a three-member tribunal drawn from three legal cultures and the first procedural conference becomes an argument about which tradition applies. International arbitration answered that argument with a compromise rather than a winner. The parties agreed to arbitrate precisely so that neither side's home procedure would govern, and the U.S. Supreme Court has long recognized that the bargain includes trading "the procedures and opportunity for review of the courtroom for the simplicity, informality, and expedition of arbitration" (Mitsubishi Motors Corp. v. Soler Chrysler-Plymouth, Inc., 473 U.S. 614 (1985); see also Scherk v. Alberto-Culver Co., 417 U.S. 506 (1974)).

The legal framework: thin by design

The national law at the seat supplies only a frame. The UNCITRAL Model Law on International Commercial Arbitration, adopted in some form by many jurisdictions, requires that the parties "be treated with equality" and that each be "given a full opportunity of presenting his case" (art. 18). Subject to that, the parties may agree on procedure, and failing agreement the tribunal may conduct the arbitration as it considers appropriate, a power that "includes the power to determine the admissibility, relevance, materiality and weight of any evidence" (art. 19). Article 26 allows tribunal-appointed experts, and article 27 lets the tribunal, or a party with its approval, ask a competent court for assistance in taking evidence. The English Arbitration Act 1996 is similar: section 34 gives the tribunal power over "all procedural and evidential matters," including whether to order disclosure and whether to apply strict rules of evidence, subject to the parties' agreement; section 43 lets a party use court procedures to secure a witness's attendance; and section 44 gives the court supporting powers, including over the taking and preservation of evidence.

The U.S. Federal Arbitration Act says almost nothing about evidence. Its only evidentiary provision is 9 U.S.C. § 7, which lets arbitrators summon a person to attend before them and bring documents. Chapter 2, which implements the New York Convention for international awards (9 U.S.C. § 201), incorporates Chapter 1 to the extent it does not conflict (9 U.S.C. § 208), so section 7 is available in U.S.-seated international cases. Everything else comes from the parties' agreement, the institutional rules, and the tribunal.

The institutional rules: a few sentences each

Institutional rules are only slightly more detailed.

None of these rules tells a tribunal how specific a document request must be, what happens to a witness who does not appear, or how to resolve a privilege claim governed by two inconsistent laws. That gap is what the IBA Rules fill. For how these rules shape the rest of the case, from the request for arbitration through the award, see Running an International Arbitration: A Practical Guide and, for AAA and ICDR practice, The Intricacies of AAA Commercial Arbitration: A Comprehensive Guide for Legal Professionals.

The IBA Rules: soft law that behaves like hard law

History and status

The International Bar Association published Supplementary Rules Governing the Presentation and Reception of Evidence in International Commercial Arbitration in 1983, replaced them with the IBA Rules on the Taking of Evidence in International Arbitration in 1999, and revised them in 2010 and again in December 2020. The 2020 revision was modest in substance but significant in timing: it added express provisions for remote hearings, a duty to consult on cybersecurity and data protection, and a power to exclude illegally obtained evidence.

The IBA Rules are not law. They bind only if the parties adopt them, in the arbitration clause or in the terms of reference, or if the tribunal orders that they apply. In practice the most common formula in Procedural Order No. 1 is that the tribunal "may be guided by" or "will have regard to" the IBA Rules. That formula gives the tribunal the IBA framework without binding it to every provision, and it is the formula most arbitrators prefer. But parties should not mistake "guidelines" for "optional." Tribunals that have announced they will be guided by the IBA Rules usually apply Article 3's requirements for document requests almost word for word, and an award that departs from them without explanation invites a due-process argument that the tribunal changed the rules mid-stream.

The governing principles

The Preamble states the IBA Rules' animating idea: the taking of evidence should be conducted on the principles that each party acts in good faith and is entitled to know, reasonably in advance of any evidentiary hearing or any fact or merits determination, the evidence on which the other parties rely. Two consequences follow. First, surprise is disfavored: documents relied on must be produced with the submissions (Article 3.1), witness statements are exchanged before the hearing (Article 4), and expert reports likewise (Article 5). Second, the burden of proof lies on the party asserting a fact, and that party is expected to prove it primarily with its own evidence.

Article 2 requires the tribunal to consult the parties at the earliest appropriate time on evidentiary issues, including the preparation of witness statements and expert reports, the taking of oral testimony, document production, confidentiality, and, since 2020, the treatment of any issues of cybersecurity and data protection. That consultation usually happens at the first case management conference and produces the evidence provisions of Procedural Order No. 1, which become the real rules of the case. Model PO1 evidence provisions are in the Arbitration Evidence Toolkit: Redfern Schedules, Witness Statement Templates, and Expert Protocols.

Document production under Article 3

The structure

Article 3 sets a two-stage process. First, each party submits with its pleadings all documents available to it on which it relies (Article 3.1). Second, within the time ordered, a party may submit a Request to Produce (Article 3.2), the other side may produce or object (Articles 3.4 and 3.5), and the tribunal rules on the objections (Article 3.7).

The content of a request, under Article 3.3, is the core of the system:

1. Identification. Either a description of each requested document sufficient to identify it, or a description in sufficient detail (including subject matter) of a "narrow and specific requested category of Documents that are reasonably believed to exist." For electronic documents, the request may, or if the tribunal orders must, identify specific files, search terms, individuals, or other means of searching efficiently and economically.
2. Relevance and materiality. A statement of how the documents are relevant to the case and material to its outcome.
3. Possession and necessity. A statement that the documents are not in the requesting party's possession, custody, or control (or why producing them would be unreasonably burdensome for the requester), and why the requester assumes the other party has them.

Each element is a filter. "All documents relating to the membrane supply contract" fails the first. A request for documents that would be interesting but would not change the outcome fails the second. A request for documents the requester already has, or that are publicly available, fails the third. The 2020 Rules continued to allow a requester to identify search terms and custodians for electronic documents, which keeps electronic requests tethered to the same "narrow and specific" discipline.

The Redfern schedule

Most tribunals require requests and objections in a single table named after the English arbitrator Alan Redfern, who popularized it. Each row is one request. The columns typically carry: the documents or category requested; the relevance and materiality explanation, with references to the pleadings; the objections; the requester's reply; and a blank column for the tribunal's decision. Some tribunals add a column for the responding party's voluntary production. The table forces each side to argue one request at a time and lets the tribunal rule in a single sitting, often in a few words per row: "Granted," "Denied (insufficiently specific)," "Granted as narrowed to the period January to June 2025."

The schedule rewards precision. A requester who explains in one paragraph why a specific engineering test report bears on a pleaded allegation, citing the paragraph of the statement of claim, usually wins that row. A requester who fills the schedule with forty broad categories teaches the tribunal to discount all of them. The step-by-step mechanics, including timetables and tactics for both sides, are in Requesting and Resisting Document Production in International Arbitration: A Practical Guide.

Relevance, materiality, and the outcome test

"Relevant to the case and material to its outcome" is the phrase tribunals return to most. Relevance asks whether the documents relate to a fact in issue. Materiality asks whether the tribunal needs them to decide the case, which tribunals often test by asking whether the fact the requester wants to prove would matter if proven. A document that proves a fact the other side has admitted is relevant but not material. A document that bears on a damages theory the tribunal has bifurcated for a later phase may be material later but not now.

Tribunals typically assess relevance and materiality "prima facie," on the parties' pleaded cases, without prejudging the merits. A requester should therefore tie each request to a specific pleaded allegation or defense. Requests aimed at discovering whether a claim exists ("fishing") are the classic ground of denial.

What happens after the order

Article 3.12 governs form: copies must conform to originals, electronic documents are produced in the form most convenient or economical to the producing party that is reasonably usable by the recipient, and translations must be provided where ordered. Article 3.13 requires the receiving party to keep produced documents confidential and use them only in connection with the arbitration. Article 3.9 lets a party ask the tribunal to take whatever steps are legally available to obtain documents from a nonparty, which in practice means seeking court assistance at the seat or in the place where the nonparty is found. Article 3.10 lets the tribunal itself request documents at any time before the arbitration ends.

Objections under Article 9

The grounds

Article 9.2 lists the grounds on which the tribunal shall, at a party's request or on its own motion, exclude documents or other evidence from production or from the record:

Article 9.3, added in 2020, lets the tribunal exclude evidence obtained illegally. The provision is discretionary, and tribunals have been receptive to excluding evidence obtained by the party's own wrongdoing while sometimes admitting documents that entered the public domain through hacking by others, depending on the circumstances. Commercial confidentiality is rarely a winning objection by itself: Article 9.5 lets the tribunal make appropriate confidentiality arrangements, such as attorneys'-eyes-only tiers, redactions, or review by an independent expert under Article 3.8, and tribunals usually prefer those tools to denying production.

Privilege: the hardest problem

Privilege in international arbitration is hard because there is no single applicable law. A U.S. company's communications with its in-house lawyer in Texas are privileged under Upjohn Co. v. United States, 449 U.S. 383 (1981), which extended the attorney-client privilege to communications between corporate counsel and lower-level employees, and U.S. courts have recognized in-house counsel's communications as privileged since at least United States v. United Shoe Machinery Corp., 89 F. Supp. 357 (D. Mass. 1950). Work product protection, rooted in Hickman v. Taylor, 329 U.S. 495 (1947), shields materials prepared in anticipation of litigation, and In re Kellogg Brown & Root, Inc., 756 F.3d 754 (D.C. Cir. 2014), confirmed that an internal investigation conducted for a significant legal purpose remains privileged. A German or French counterpart's communications with its in-house counsel may receive narrower protection or none. In the European Union, the Court of Justice held in Akzo Nobel Chemicals Ltd and Akcros Chemicals Ltd v. European Commission (Case C-550/07 P, 2010) that communications with in-house lawyers were not protected by legal professional privilege in Commission competition investigations, because in-house lawyers lack the independence of outside counsel. English law, by contrast, protects in-house lawyers' legal advice on the same footing as outside counsel's, and distinguishes legal advice privilege from litigation privilege.

U.S. courts facing the same problem in litigation use choice-of-law tests: a "touch base" or comity analysis that applies the law of the country with the predominant interest in the communication, as in Golden Trade, S.r.L. v. Lee Apparel Co., 143 F.R.D. 514 (S.D.N.Y. 1992), with Fed. R. Evid. 501 supplying federal common law in federal-question cases. Tribunals are not bound by those tests, and Article 9.2(b) leaves the applicable rules to the tribunal's determination. Article 9.4 lists what the tribunal may take into account:

• the need to protect the confidentiality of a document or communication made in connection with and for the purpose of providing or obtaining legal advice;
• the need to protect the confidentiality of settlement negotiations;
• the expectations of the parties and their advisors at the time the privilege is said to have arisen;
• any possible waiver, by consent, earlier disclosure, affirmative use of the document or its contents, or otherwise; and
• the need to maintain fairness and equality between the parties, particularly if they are subject to different legal or ethical rules.

From those factors tribunals have built three approaches. The closest connection approach applies the privilege law of the jurisdiction most closely connected with the communication, usually where the lawyer practices or where the relationship is centered. It respects the parties' expectations but can produce inequality: the U.S. party withholds its in-house advice while the German party must produce its own. The most favored nation (or "most protective rule") approach applies to both parties the most protective of the potentially applicable rules, so that each side receives at least the protection the other has. It honors the equality factor and is increasingly common, especially when the tribunal raises it in PO1 and the parties agree. The least protective rule approach is rarely used because it defeats expectations. Some tribunals combine approaches, applying the closest connection test to identify each party's rule and then extending the more protective rule to both sides for equality.

The practical lesson is to raise privilege at the first procedural conference, not in the Redfern schedule. A PO1 clause that adopts a most-favored-nation rule, defines what a privilege log must contain, and sets a clawback rule for inadvertent production (analogous to Fed. R. Evid. 502 in U.S. courts) prevents months of argument. For the underlying U.S. doctrine, see Attorney-Client Privilege and Work Product for Businesses: Upjohn, In-House Counsel, and the Common Interest, and for log mechanics, Preparing a Privilege Log: A Practical Checklist.

Adverse inferences and other consequences

International tribunals do not hold parties in contempt. Their sanction for non-production is inferential. Article 9.6 provides that if a party fails without satisfactory explanation to produce a document requested in a Request to Produce to which it has not objected in due time, or fails to produce a document ordered by the tribunal, the tribunal may infer that the document would be adverse to that party's interests. Article 9.7 applies the same logic to other evidence, including testimony. Article 9.8 lets the tribunal take a party's failure to conduct itself in good faith into account in allocating costs.

Tribunals are cautious with inferences. The commentary and practice reflect a set of conditions that a party seeking an inference should satisfy: the requesting party produced all available evidence corroborating the inference sought; the documents were within the other party's control; the inference is reasonable, consistent with the facts in the record, and logically related to the likely nature of the withheld evidence; the requesting party made a prima facie case; and the other party knew or should have known that it was expected to produce and was given an opportunity to do so. The inference is a tool for filling a gap in the record, not a substitute for proof. A claimant that has no evidence of a fact cannot win on an inference alone.

The contrast with U.S. practice is worth noticing. Under Fed. R. Civ. P. 37(e), as amended in 2015, a federal court may give an adverse-inference instruction for lost electronically stored information only on a finding of intent to deprive, a narrowing of the more lenient negligence-based approach of Residential Funding Corp. v. DeGeorge Financial Corp., 306 F.3d 99 (2d Cir. 2002). Article 9.6 contains no intent requirement, only the absence of a satisfactory explanation. U.S. parties who assume their home standard applies are sometimes surprised. Tribunals also have authority, under broad arbitration clauses and institutional rules, to sanction bad faith through costs; U.S. courts have upheld such awards, as in ReliaStar Life Insurance Co. of New York v. EMC National Life Co., 564 F.3d 81 (2d Cir. 2009). The analogous U.S. court process is covered in Motions to Compel and Discovery Sanctions Under Rule 37: From Meet and Confer to Default Judgment.

Witnesses of fact: the written statement and the live hearing

Who can testify

In many civil-law systems a party, or a party's director, cannot testify as a witness in its own case. International arbitration rejects that limit. Article 4.2 of the IBA Rules provides that any person may present evidence as a witness, including a party or a party's officer, employee, or other representative, and article 27(2) of the UNCITRAL Rules says the same. The tribunal weighs the witness's interest in the outcome rather than excluding the testimony.

Preparation: what counsel may do

Article 4.3 provides that it is not improper for a party, its officers, employees, legal advisors, or other representatives to interview its witnesses or potential witnesses and to discuss their prospective testimony with them. Article 20 of the LCIA Rules is to similar effect. That provision settles a question that once divided practitioners. Swiss and some other civil-law bar traditions historically discouraged substantive pre-hearing contact with witnesses; English barristers are prohibited from "coaching" witnesses, though they may familiarize them with the process; U.S. lawyers prepare witnesses extensively, subject to rules against counseling false testimony, and U.S. courts police the line during testimony itself (compare Geders v. United States, 425 U.S. 80 (1976), on a criminal defendant's right to consult counsel during an overnight recess, with Hall v. Clifton Precision, 150 F.R.D. 525 (E.D. Pa. 1993), barring private conferences between a deponent and counsel during a deposition).

The IBA Guidelines on Party Representation in International Arbitration (2013) supply the professional standards. In substance, they provide that a party representative should not knowingly assist in presenting false evidence, should inform witnesses that they may and should give truthful testimony, should ensure a witness statement reflects the witness's own account of the relevant facts and an expert report the expert's own analysis and opinion, may assist in preparing statements and reports, and may meet witnesses and experts to discuss and prepare their testimony, so long as compensation is reasonable and not contingent on the outcome. Tribunals increasingly incorporate those guidelines by reference in PO1, which gives them a measuring stick when one side accuses the other of scripting testimony.

The statement itself

Article 4.5 lists what a witness statement must contain: the witness's full name and address, a statement of the witness's present and past relationship with any of the parties, and a description of background, qualifications, training, and experience if relevant; a full and detailed description of the facts and the source of the witness's information as to those facts, sufficient to serve as that witness's evidence in the matter in dispute; any documents on which the witness relies that have not already been submitted; a statement as to the language in which the statement was originally prepared and the language in which the witness anticipates giving testimony; an affirmation of the truth of the statement; and the witness's signature, date, and place. Article 4.6 allows revised or additional statements limited to responding to matters in another party's statements, expert reports, or submissions, or to new developments.

A statement drafted by counsel in counsel's voice is the most common failing in the system. Tribunals notice when a production engineer from Hamburg writes like a London barrister, and cross-examination built on that observation ("these are not your words, are they?") is effective. The best statements are written from interview notes in the witness's own vocabulary, use the witness's own documents, distinguish what the witness saw from what the witness was told, and avoid argument. Templates and drafting notes are in the Arbitration Evidence Toolkit: Redfern Schedules, Witness Statement Templates, and Expert Protocols.

The witness who does not appear

The written statement is only half the bargain. If a party's witness is called for cross-examination and fails without valid reason to appear, Article 4.7 directs the tribunal to disregard that witness's statement unless, in exceptional circumstances, it decides otherwise. If no party calls a witness for cross-examination, Article 4.8 provides that the absence of a request does not mean the other side accepts the statement as correct. A party that leaves a damaging statement unchallenged takes a risk: the tribunal can still give it weight.

At the hearing

Because the statement stands as direct testimony, hearing time is mostly cross-examination, followed by limited re-direct and questions from the tribunal. Article 8 gives the tribunal "complete control" over the evidentiary hearing, including the power to limit or exclude questions and to vary the order of testimony. Tribunals usually allow a short direct examination, perhaps ten or fifteen minutes, so the witness can confirm the statement, correct errors, and respond to new matters, and they apply chess-clock time limits to each side's total hearing time. The art of cross-examination in this setting differs from a U.S. jury trial: there is no jury to perform for, tribunals dislike repetitive questioning, and leading questions are permitted but less rewarding than a document-driven sequence that walks the witness to an admission. For technique, see Cross-Examination Methods Compared: Pozner-Dodd, Younger's Ten Commandments, the Reptile, and the Reid Technique, and adapt what works before a judge rather than a jury.

Sequestration also works differently. Under Fed. R. Evid. 615, a U.S. court must exclude witnesses at a party's request. In arbitration, fact witnesses are often allowed to attend the hearing before they testify unless the tribunal orders otherwise, and party representatives who are also witnesses usually may attend throughout. PO1 should address the point expressly, together with the rule that counsel may not discuss the substance of testimony with a witness once cross-examination begins.

Expert evidence

Party-appointed experts

Article 5 governs experts retained by the parties. The report under Article 5.2 must contain the expert's full name and address, present and past relationship with the parties, their legal advisors, and the tribunal, and a description of background, qualifications, training, and experience; a description of the instructions under which the expert provides opinions; a statement of independence from the parties, their legal advisors, and the tribunal; a statement of the facts on which the opinions are based; the opinions and conclusions, including a description of the methods, evidence, and information used; the documents relied on; an affirmation of the expert's genuine belief in the opinions; and signature, date, and place. Reply reports are allowed under Article 5.3. Under Article 5.4 the tribunal may order experts to meet and confer to identify where they agree and disagree, and to record those points in writing, a joint report that often narrows the hearing considerably.

Two features surprise U.S. lawyers. First, there is no Rule 26(b)(4)-style protection for drafts and attorney-expert communications unless PO1 creates one. Because Article 5.2 requires disclosure of the expert's instructions, tribunals sometimes order production of instruction letters, and counsel should draft them expecting the tribunal to read them. Second, there is no Daubert gatekeeping. Arbitrators are not bound by Fed. R. Evid. 702 or by Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) and Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999); unreliable methodology goes to weight, not admissibility. That makes the expert's independence and the transparency of the method, rather than a pretrial exclusion motion, the main battleground. The U.S. framework is in Expert Witnesses After the 2023 Amendment to Rule 702: Daubert, Disclosure, and Cross-Examination.

Independence has an institutional dimension as well. The IBA Guidelines on Conflicts of Interest in International Arbitration (revised in 2024) govern arbitrators, not experts, but they treat close relationships between an arbitrator and a party's expert as matters that may call for disclosure, and some tribunals have excluded an expert, or counsel, whose late appearance would create a conflict with a sitting arbitrator. Ask early whether a proposed expert has relationships with any member of the tribunal.

Tribunal-appointed experts

Article 6 permits the tribunal, after consulting the parties, to appoint one or more independent experts. The expert must provide a statement of independence before accepting, and the parties may object (Article 6.2). The expert may request information and documents from the parties (Article 6.3), reports in writing (Article 6.4), and may be questioned by the parties at the hearing (Article 6.6). ICC Rules article 25(4), UNCITRAL Rules article 29, LCIA Rules article 21, and Model Law article 26 contain parallel powers. U.S. litigators know the device from Fed. R. Evid. 706, which is rarely used; in international arbitration, tribunal-appointed experts are more common, especially where the tribunal includes civil-law arbitrators or the issues are highly technical (quantity surveying, valuation of an unlisted company, metallurgy). The party-appointed experts usually remain in the case, and their role shifts to commenting on the tribunal expert's work.

Witness conferencing and the Sachs protocol

Article 8 lets the tribunal arrange testimony by issue or have witnesses "questioned at the same time and in confrontation with each other," which practitioners call witness conferencing and, when applied to experts, concurrent evidence or "hot-tubbing," a term borrowed from Australian court practice. In a typical expert conference, both quantum experts sit together; each gives a short presentation; the tribunal leads a discussion issue by issue from the joint report's list of disagreements; each expert may question the other; and counsel cross-examine at the end. The format exposes weak positions quickly, because an expert who will not concede an obvious point in front of a peer loses credibility in real time. It disadvantages experts who are better at advocacy than analysis, and counsel lose some control, which is why some counsel resist it.

A more radical proposal, associated with the German arbitrator Klaus Sachs and first presented in 2010, is sometimes called the Sachs protocol or "expert teaming." Each party nominates a list of candidate experts; the tribunal selects one from each list; and the two selected experts work together as a single tribunal-appointed team that produces one joint report. The proposal aims to combine the parties' confidence in experts they chose with the neutrality of a tribunal appointment. It is cited more than it is used, but it is a useful option to offer when both sides fear a single tribunal expert. Model language for expert meetings, joint reports, and conferencing is in the Arbitration Evidence Toolkit: Redfern Schedules, Witness Statement Templates, and Expert Protocols, and a phase-by-phase task list is in the Witness and Expert Evidence in International Arbitration Checklist: A Practical Checklist.

Hearings, remote testimony, cybersecurity, and data protection

The pandemic turned remote hearings from an exception into a routine option, and the rules followed. Article 8.2 of the 2020 IBA Rules allows the tribunal, at a party's request or on its own motion and after consulting the parties, to order that the evidentiary hearing be conducted as a remote hearing, and requires consultation on a remote hearing protocol addressing the technology, advance testing, time zones, the presentation of documents, and measures to ensure that witnesses testifying remotely are not improperly influenced or distracted. ICC Rules article 26(1) (2021) provides that hearings may take place in person or remotely by videoconference, telephone, or other appropriate means of communication, and LCIA Rules article 19 (2020) is similar. Courts in several jurisdictions have upheld awards rendered after remote hearings over a party's objection, though the law at the seat should be checked where a party insists on its right to an in-person hearing. The logistics overlap heavily with remote depositions; see Remote Video Depositions: Logistics, Remote Exhibits, Objections, and the Off-Camera Coaching Problem. The off-camera coaching problem is the same problem, and the same solutions (camera positioning, no other applications open, a statement that no one else is in the room) appear in arbitral protocols.

Evidence now moves through data rooms, e-filing platforms, and video links, which makes it a cybersecurity target. The ICCA-NYC Bar-CPR Protocol on Cybersecurity in International Arbitration (2020 edition) recommends that the tribunal and parties consider, early in the case, the reasonable security measures for the matter given its risk profile, such as encrypted transfer, access controls, and breach notification. Data protection law adds another layer. Where personal data of EU residents are processed, the General Data Protection Regulation applies to parties, counsel, and often arbitrators; the ICCA-IBA Roadmap to Data Protection in International Arbitration (2022) explains how lawful bases (often legitimate interests), the data minimization principle, and the transfer rules, including the derogation for transfers necessary for the establishment, exercise, or defense of legal claims, apply to document production and hearing bundles. Data protection is rarely a reason to refuse production outright, but it is a good reason for redaction, pseudonymization, and production protocols. U.S. courts take a similar view of foreign blocking and privacy statutes in litigation, weighing comity under Société Nationale Industrielle Aérospatiale v. U.S. District Court, 482 U.S. 522 (1987), rather than treating them as automatic bars. For transfer mechanics, see International Data Transfers After Schrems II: Standard Contractual Clauses and Transfer Impact Assessments.

The Prague Rules: an inquisitorial alternative

In December 2018 a working group of mainly civil-law practitioners launched the Rules on the Efficient Conduct of Proceedings in International Arbitration, known as the Prague Rules. Their premise is that the IBA Rules, despite their reputation as a compromise, import too much common-law practice and cost. The Prague Rules ask the tribunal to take a more active role: to hold an early case management conference, to identify the facts that are undisputed and those that require proof, and, where appropriate, to share its preliminary views with the parties (arts. 2 and 3). On documents, article 4 encourages the tribunal and the parties to avoid any form of document production, including e-discovery, and allows a party to request specific documents only where it shows they are relevant and material, not in the public domain, and in the other party's possession. On witnesses, article 5 lets the tribunal decide which witnesses to call and whether to hear a witness at all. On experts, article 6 favors tribunal-appointed experts. Article 9 allows the tribunal, unless a party objects, to assist the parties in reaching an amicable settlement (an arbitrator may act as mediator only with the parties' express consent), and article 10 addresses adverse inferences.

The Prague Rules remain less widely adopted than the IBA Rules, and their settlement-facilitation provision makes common-law counsel uneasy because a tribunal that has heard confidential settlement positions may later have to decide the case. But their ideas have influenced practice even where they are not adopted: many tribunals now hold earlier and more substantive case management conferences, limit document production more tightly, and express preliminary views on issues. A party that wants a fast, document-light process, or that faces a counterparty with vast document holdings and no corresponding need for production, should consider proposing them. For settlement dynamics during an arbitration, see Settlement Negotiation Tactics: Principled Negotiation, Anchoring, and Handling Hardball in Litigation.

Investor-state cases and the ICSID Rules

Treaty arbitration adds two complications: one party is a state, and documents may be classified or politically sensitive. The ICSID Arbitration Rules (2022) codify much of what tribunals were already doing. Rule 37 directs the tribunal, in resolving document production disputes, to consider the scope and timeliness of the request, the relevance and materiality of the documents, the burden of production, and the basis of the objection. States frequently invoke Article 9.2(f) of the IBA Rules (special political or institutional sensitivity), and tribunals often respond with redaction, privilege-style logs, or review by the tribunal or a neutral. Public interest in the proceedings also complicates confidentiality, because transparency rules (including the UNCITRAL Rules on Transparency in Treaty-based Investor-State Arbitration) may require publication of submissions and hearings. For the broader framework, see Investor-State Arbitration: Treaty Protections, Jurisdiction, and the Enforcement of Awards Against States and the Treaty Arbitration Toolkit: Notices of Dispute, Jurisdictional Objections, and Enforcement Strategy.

What U.S. courts can add

Section 1782 after ZF Automotive

For two decades, U.S. lawyers in international arbitration watched a circuit split over whether 28 U.S.C. § 1782, which lets a district court order a person who "resides or is found" in its district to give testimony or produce documents "for use in a proceeding in a foreign or international tribunal," reached private arbitral tribunals. Intel Corp. v. Advanced Micro Devices, Inc., 542 U.S. 241 (2004), read the statute broadly in a case involving the European Commission and set out the discretionary factors courts still apply, but it did not decide the arbitration question. The Second and Fifth Circuits had held private arbitration outside the statute (National Broadcasting Co. v. Bear Stearns & Co., 165 F.3d 184 (2d Cir. 1999); Republic of Kazakhstan v. Biedermann International, 168 F.3d 880 (5th Cir. 1999)). The Sixth and Fourth Circuits later held it inside (In re Application to Obtain Discovery for Use in Foreign Proceedings, 939 F.3d 710 (6th Cir. 2019); Servotronics, Inc. v. Boeing Co., 954 F.3d 209 (4th Cir. 2020)), and the Seventh Circuit disagreed (Servotronics, Inc. v. Rolls-Royce PLC, 975 F.3d 689 (7th Cir. 2020)).

ZF Automotive US, Inc. v. Luxshare, Ltd., 596 U.S. 619 (2022), resolved the split unanimously. The Court held that a "foreign or international tribunal" is one that exercises governmental or intergovernmental adjudicative authority. A private commercial arbitral panel seated in Germany did not qualify. Neither did an ad hoc tribunal constituted under a bilateral investment treaty, decided with it (the AlixPartners case), because nothing in the treaty showed that the states intended to give the panel governmental authority. Section 1782 remains available for foreign court proceedings, including court proceedings connected to an arbitration (an annulment action at the seat, an interim-measures application, or an enforcement proceeding abroad), subject to the Intel factors and the statute's territorial reach as construed in In re del Valle Ruiz, 939 F.3d 520 (2d Cir. 2019). The Court left open that a treaty could create a tribunal with governmental authority, so whether a particular treaty-based or institutional tribunal qualifies depends on the instrument that created it; check recent decisions in the district where you would file before relying on section 1782 in an investor-state case. The full analysis is in Section 1782 Discovery in Aid of Foreign Proceedings: Who Can Ask, What They Get, and What ZF Automotive Changed, and the application process in Seeking or Opposing Section 1782 Discovery: A Practical Guide.

Arbitrator subpoenas under FAA Section 7

Section 7 survives ZF and applies to U.S.-seated arbitrations, international or domestic. It lets arbitrators "summon in writing any person to attend before them or any of them as a witness and in a proper case to bring with him or them any book, record, document, or paper which may be deemed material as evidence in the case." If the person refuses, the district court for the district in which the arbitrators are sitting may compel attendance. The circuits have read the text in two ways.

The majority view is that section 7 does not authorize pre-hearing document discovery from nonparties. In Hay Group, Inc. v. E.B.S. Acquisition Corp., 360 F.3d 404 (3d Cir. 2004), the court, in an opinion by then-Judge Alito, held that the statute's language speaks only of summoning a nonparty to appear before the arbitrators and bring documents; a concurrence by Judge Chertoff observed that arbitrators can achieve much the same result by convening a hearing, even before a single arbitrator, at which the nonparty appears with the documents. The Second Circuit agreed in Life Receivables Trust v. Syndicate 102 at Lloyd's of London, 549 F.3d 210 (2d Cir. 2008), as did the Ninth in CVS Health Corp. v. Vividus, LLC, 878 F.3d 703 (9th Cir. 2017), and the Eleventh in Managed Care Advisory Group, LLC v. CIGNA Healthcare, Inc., 939 F.3d 1145 (11th Cir. 2019). The Second Circuit has confirmed that arbitrators may compel a nonparty to appear and produce documents at a hearing before the panel even if it is not the final merits hearing (Stolt-Nielsen SA v. Celanese AG, 430 F.3d 567 (2d Cir. 2005)). The Fourth Circuit took an intermediate view in COMSAT Corp. v. National Science Foundation, 190 F.3d 269 (4th Cir. 1999), suggesting pre-hearing discovery might be compelled on a showing of special need or hardship. The Eighth Circuit, in In re Security Life Insurance Co. of America, 228 F.3d 865 (8th Cir. 2000), found an implicit power to order pre-hearing production of documents from a nonparty that was closely involved in the dispute.

Section 7 subpoenas also have a geographic limit. In Dynegy Midstream Services, LP v. Trammochem, 451 F.3d 89 (2d Cir. 2006), the Second Circuit held that the FAA does not authorize nationwide service of arbitral summonses, so enforcement is tied to the district where the arbitrators sit and the territorial limits that Fed. R. Civ. P. 45 imposes. Courts have not settled whether section 7 lets arbitrators compel a nonparty to appear by video at a remote hearing rather than physically before them, so check the current position in the relevant circuit before relying on a remote summons. The practical response in many international cases is the "Hay Group hearing": the tribunal (or one member) convenes a short evidentiary session in the city where the nonparty is located, the nonparty appears with documents, and the session is adjourned.

Court assistance elsewhere

Outside the United States, court assistance comes from the law of the seat or of the place where the evidence is found. Model Law article 27 lets the tribunal, or a party with its approval, request assistance from a competent court. Under the English Arbitration Act 1996, a party may use court procedures to secure a witness's attendance in the United Kingdom with the tribunal's permission or the other parties' agreement (section 43), and the court has supporting powers over the taking and preservation of evidence (section 44). The Arbitration Act 2025, whose substantive provisions took effect on 1 August 2025, amended section 44(1) so that the court's powers may be exercised "whether in relation to a party or any other person," settling that section 44 orders can reach third parties. Where evidence sits abroad and no court assistance route exists, Hague Evidence Convention requests and letters rogatory under 28 U.S.C. § 1781 generally serve courts rather than tribunals, though a court at the seat may sometimes issue a request on a tribunal's behalf. For the litigation toolkit, see the Cross-Border Discovery Toolkit: 1782 Applications, Hague Requests, and Blocking Statute Analyses.

Evidentiary rulings at the annulment and enforcement stage

The legal hooks

An evidentiary ruling can be attacked in three places. At a U.S. seat, 9 U.S.C. § 10(a)(3) allows vacatur where the arbitrators were "guilty of misconduct ... in refusing to hear evidence pertinent and material to the controversy." Awards rendered in the United States in international cases may be vacated on the FAA's domestic grounds (Yusuf Ahmed Alghanim & Sons, W.L.L. v. Toys "R" Us, Inc., 126 F.3d 15 (2d Cir. 1997)), and those grounds are exclusive (Hall Street Associates, L.L.C. v. Mattel, Inc., 552 U.S. 576 (2008)). At a Model Law seat, article 34(2)(a)(ii) allows set-aside where a party was "unable to present his case." At the place of enforcement, Article V(1)(b) of the New York Convention, implemented in the United States through 9 U.S.C. § 207, permits refusal where the party against whom the award is invoked "was otherwise unable to present his case," and Article V(2)(b) where enforcement would be contrary to the public policy of the enforcing country. Article V(1)(d) adds a defense where the arbitral procedure was not in accordance with the parties' agreement, which is why a tribunal that departs from rules the parties adopted takes a risk.

The cases as stories

The invoice that was never filed. In Iran Aircraft Industries v. Avco Corp., the claim before the Iran-United States Claims Tribunal turned on invoices. At a pre-hearing conference, the chairman approved Avco's proposal to submit summaries of its invoices, audited by an accounting firm, rather than the voluminous invoices themselves. A differently constituted panel then rejected the claim for lack of the underlying invoices. The Second Circuit refused enforcement under Article V(1)(b) because the tribunal had misled Avco about the evidence it needed and then penalized it for following that guidance (980 F.2d 141). The lesson for tribunals is consistency; for counsel, it is to get evidentiary agreements recorded in a procedural order.

The witness who could not come. In Parsons & Whittemore Overseas Co. v. Société Générale de l'Industrie du Papier (RAKTA), 508 F.2d 969 (2d Cir. 1974), the American party complained that the tribunal refused to delay the hearing so a key witness could attend. The Second Circuit held that the inability to produce one's chosen witness was a risk inherent in agreeing to arbitrate and did not violate Article V(1)(b), and it read the public policy defense narrowly, to apply only where enforcement would violate the forum's "most basic notions of morality and justice."

The limited cross-examination. In Generica Ltd. v. Pharmaceutical Basics, Inc., 125 F.3d 1123 (7th Cir. 1997), the arbitrator restricted cross-examination of a witness. The Seventh Circuit held that this did not deny the party a fundamentally fair hearing; arbitrators are not bound to hear all evidence tendered, so long as each side has an adequate opportunity to present its case.

The discovery that was denied. In Karaha Bodas Co. v. Perusahaan Pertambangan Minyak Dan Gas Bumi Negara, 364 F.3d 274 (5th Cir. 2004), the Indonesian state oil company argued that the tribunal's refusal to order discovery and its scheduling decisions left it unable to present its case. The Fifth Circuit rejected the argument, emphasizing the tribunal's broad discretion over procedure and the absence of any showing that the rulings caused real prejudice.

The witness the panel would not wait for. On the other side of the line is Tempo Shain Corp. v. Bertek, Inc., 120 F.3d 16 (2d Cir. 1997). The panel closed the hearings without the testimony of a witness who was unavailable because of a family medical emergency, reasoning that his evidence would be cumulative. The Second Circuit vacated under section 10(a)(3), because the witness was the only one who could testify to certain fraudulent-inducement facts and there was no reasonable basis for treating his testimony as cumulative. A similar result followed in Hoteles Condado Beach v. Union de Tronquistas Local 901, 763 F.2d 34 (1st Cir. 1985), where the arbitrator gave no weight to the only evidence of the underlying incident, a transcript of prior testimony, which the court treated as a refusal to consider pertinent and material evidence.

Due process paranoia

The pattern is clear: courts defer to tribunals' evidentiary discretion, but a tribunal that excludes the only evidence on a decisive point, or changes the evidentiary ground rules after a party relied on them, risks the award. Tribunals know this, and the result is a phenomenon practitioners call "due process paranoia": tribunals admit late evidence, grant extensions, and hear marginal witnesses because a refusal might later be characterized as denying a party the chance to present its case. Counsel can use this in both directions. A party seeking to admit late evidence should frame the request in due-process terms. A party opposing it should propose a cure (a short reply submission, a supplementary witness statement) that removes the due-process risk, which makes it easier for the tribunal to rule in its favor on everything else. For the enforcement framework, see International Arbitration and the New York Convention: Enforcing Awards Across Borders and Confirming and Vacating Arbitration Awards: The Narrow Door of FAA Review.

Practical implications for each side

For the claimant. Build the case on the documents you already have before the arbitration starts, because the tribunal will expect your statement of claim to be supported by exhibits and witness statements, and document production comes later and gives less than you hope. Identify, before filing, the specific documents you need from the respondent and the pleaded allegations they prove, so you can draft the statement of claim to make those documents material. Preserve your own documents rigorously; the respondent's best production requests will target your internal assessments of the claim.

For the respondent. Read the statement of claim as a document request in disguise: every allegation the claimant cannot prove with its own documents is a request you will receive. Decide early whether to propose the Prague Rules or a tight production regime. Review your own documents early and candidly, because the risk of an adverse inference grows when a party resists production of a category it later turns out to hold. And identify privilege conflicts before PO1, especially if your in-house lawyers sit in a jurisdiction with weaker protection than the claimant's.

For both. Use the first case management conference to settle the evidence rules: whether the IBA Rules bind or guide, the privilege rule, the production timetable and format, the witness statement rules (including whether reply statements are allowed), expert meetings and conferencing, sequestration, remote testimony, cybersecurity, and data protection. Every one of those points is cheaper to agree in PO1 than to litigate later. The International Arbitration Toolkit: Clauses, Procedural Orders, and Enforcement Petitions has an outline PO1.

Extended worked example: Brightwater v. Nordhavn

The dispute. Brightwater Desalination, Inc., a Houston company, bought reverse-osmosis membranes from Nordhavn Membranes GmbH of Hamburg for three desalination plants it operates in the Gulf region. Within eighteen months, the membranes at two plants fouled and failed at rates far above the contract specification. Brightwater replaced them at a cost it puts at USD 48 million, including lost output. The contract has an ICC clause, seated in New York, English language, three arbitrators, New York law. Brightwater says Nordhavn changed a polymer supplier without notice and knew from its own testing that the new material degraded faster in high-salinity feed water. Nordhavn says Brightwater's pretreatment system, designed by a New Jersey engineering firm, Calder Water Engineering LLC, was operated outside its parameters.

PO1. The tribunal (a Swiss chair, a U.S. co-arbitrator, a German co-arbitrator) proposes that it "be guided by" the IBA Rules. Brightwater's counsel, anticipating a privilege fight, proposes and Nordhavn accepts a clause applying the most protective privilege rule of any jurisdiction with a close connection to the communication, equally to both parties. Brightwater also proposes that experts meet and prepare a joint statement after the second round of reports and that the hearing include expert conferencing. Nordhavn proposes, and the tribunal accepts, that each side may make no more than 25 requests to produce. The tribunal adds a remote-testimony protocol for witnesses based in the Gulf, and a cybersecurity paragraph requiring encrypted transfer of document productions and a shared platform with two-factor authentication. The order addresses GDPR by requiring that productions of employee personal data be limited to what the request requires and that irrelevant personal data be redacted.

Document production. Brightwater's Redfern schedule includes a request for "the test reports, laboratory notebooks, and internal emails of Nordhavn's Materials Testing Group, between 1 March and 31 October 2024, concerning accelerated aging or salinity-tolerance testing of membranes manufactured with polymer from the replacement supplier," with search terms and four named custodians. It explains that the documents are material to paragraphs 41 to 47 of the statement of claim (knowledge) and to Nordhavn's defense that the failures had another cause. The tribunal grants it. A second request, for "all documents concerning Nordhavn's supplier changes from 2020 to the present," is denied as insufficiently narrow and specific.

Nordhavn requests Brightwater's "internal assessments of the cause of the membrane failures." Brightwater objects on privilege for a root-cause memorandum prepared by its in-house counsel after the failures, invoking Upjohn and Kellogg Brown & Root. Under the most-favored-nation clause, the memorandum is privileged for the legal-advice portions; the tribunal orders production of the attached factual data (operating logs and feed-water analyses), which no privilege protects. Nordhavn in turn claims privilege over a memo by its in-house lawyer, Dr. Lena Vogt, on the supplier change. Under German law alone the protection might have been contested; under the PO1 clause it receives the same protection Brightwater's memo did. Both sides avoid a months-long argument.

The nonparty. Nordhavn wants Calder's pretreatment design files. Calder is not a party and refuses a voluntary request. Because the tribunal sits in New York, Nordhavn asks it to issue a section 7 summons. The tribunal, mindful of Hay Group and Life Receivables, schedules a half-day evidentiary session in Newark, attended in person by the U.S. co-arbitrator and remotely by the others, at which a Calder records custodian appears with the files. Nordhavn does not attempt a section 1782 application, which after ZF Automotive would fail for a private ICC tribunal.

The inference. Nordhavn produces test reports for March through June 2024 but none for July through October, explaining that a laboratory server migration lost the files. Brightwater asks for an adverse inference under Article 9.6. The tribunal requires Nordhavn to submit a witness statement from its IT manager on the migration and permits Brightwater a short reply. At the hearing, the IT manager concedes that the migration was planned after the arbitration request was received and that no litigation hold was issued for the testing group. In the award, the tribunal infers that the missing reports would have shown continued degradation, but treats the inference as corroborating, not replacing, Brightwater's other evidence: two emails among the produced documents in which a Nordhavn engineer described the new polymer as "not where we need it for Gulf feed."

The experts. Each side files two expert reports, a membrane chemist and a quantum expert. The chemists meet and produce a joint statement agreeing on the degradation mechanism but disagreeing on whether pretreatment failures contributed. At the hearing the tribunal conferences the chemists for three hours, issue by issue. Nordhavn's chemist concedes that the operating logs show pretreatment within range at one of the two plants. The quantum experts agree on the replacement cost but disagree on lost output, which the tribunal resolves by preferring Brightwater's expert's method and Nordhavn's expert's discount rate.

The award and enforcement. The tribunal awards USD 39 million. Nordhavn moves to vacate in the Southern District of New York under section 10(a)(3), arguing that the adverse inference and the limits on its document requests denied it a fair hearing. The court, applying the deferential standard reflected in Generica and Karaha Bodas, confirms the award: Nordhavn had notice, an opportunity to explain the missing files, and a full hearing. Brightwater then seeks recognition in Germany under the New York Convention, where Nordhavn's Article V(1)(b) argument fails for the same reason. Every ruling Nordhavn attacked had been made after notice and an opportunity to respond, which is what defeated both challenges.

Common mistakes

1. Treating "guided by the IBA Rules" as a free pass. Tribunals apply Article 3.3 strictly. Draft requests as if the Rules bind.
2. Filing forty broad requests. Volume destroys credibility. Twelve precise requests that track the pleadings usually yield more documents than forty vague ones.
3. Leaving privilege for later. The time to agree a privilege rule is PO1, when neither side yet knows which documents will matter.
4. Ignoring your own documents. The other side's best requests target your internal analyses. Review and preserve before the request arrives.
5. Writing the witness statement for the witness. Cross-examination exposes counsel-drafted statements quickly. Use the witness's words and documents.
6. Assuming U.S. expert protections apply. Without a PO1 clause, instructions and some communications may be disclosable. Write instruction letters for the tribunal's eyes.
7. Filing a section 1782 application in aid of a private arbitration. After ZF Automotive it will fail; look instead at section 7, Model Law article 27, or court proceedings connected to the arbitration.
8. Serving a section 7 subpoena for pre-hearing production in a majority-rule circuit. Ask the tribunal to convene a hearing instead.
9. Forgetting the record for enforcement. A due-process objection not raised before the tribunal is usually waived. Object promptly, on the record, and propose a cure.
10. Treating data protection as an afterthought. A production containing unredacted personal data of EU employees can create regulatory exposure for the producing party and its counsel.

Frequently asked questions

Can I depose the other side's witnesses? Not as of right. Some tribunals allow limited depositions by agreement, especially in U.S.-seated cases between U.S. parties, but the norm is a written statement followed by cross-examination at the hearing.

Are the IBA Rules binding? Only if the parties agree or the tribunal orders that they bind. Most PO1s say the tribunal will be "guided by" them, which in practice means the core provisions are applied unless the tribunal explains a departure.

What is a Redfern schedule? A table in which each document request appears in a row, with columns for the request, its relevance and materiality, the objection, the reply, and the tribunal's ruling. Templates are in the Arbitration Evidence Toolkit: Redfern Schedules, Witness Statement Templates, and Expert Protocols.

Does the tribunal apply U.S. privilege law? Only if it decides that law applies. Under Article 9.2(b) and 9.4, the tribunal chooses the applicable rules, often by a closest-connection test, a most-favored-nation approach, or a combination.

Can the tribunal punish a party that hides documents? It can draw an adverse inference (Article 9.6), disregard evidence (Article 9.7), and shift costs (Article 9.8). It cannot hold a party in contempt; that requires a court.

Can I get evidence from a nonparty? Sometimes. In a U.S.-seated case, a section 7 summons can compel a nonparty to appear before the arbitrators with documents, subject to the circuit's reading of the statute. Elsewhere, court assistance depends on the law of the seat or the place where the nonparty is located.

Do I need an expert if the tribunal appoints one? Usually yes. Party-appointed experts help the tribunal evaluate the tribunal expert's work, and Article 6 lets the parties question the tribunal expert at the hearing.

Will a remote hearing affect enforcement? Generally not where the parties had notice and an equal opportunity to participate, but where a party objected, check the law of the seat and the likely enforcement jurisdictions before proceeding.

Takeaways

• The evidence rules of an international arbitration are made in Procedural Order No. 1. Arrive at the first conference with a position on every evidentiary issue.
• Document production is a narrow, request-by-request exercise. Tie every request to a pleaded fact, a time period, and custodians.
• Privilege is a choice-of-law problem. Solve it with an agreed rule, ideally one that treats both sides equally.
• The sanction is inferential. Preserve your own documents, and build a record before asking for an inference against the other side.
• Witness statements and expert reports are the evidence-in-chief. Make them the witness's and the expert's own work.
• Expect the experts to meet and, often, to testify together.
• U.S. courts help less than U.S. lawyers expect: no section 1782 for private arbitration, and section 7 mostly for hearings.
• Evidentiary rulings survive review when the tribunal gave notice and a fair opportunity to respond. Make sure the record shows both.

This document is general information, not legal advice for any particular situation; arbitral rules and national law change, and the facts of each case matter.

Related Documents

Related Articles

• International Arbitration and the New York Convention: Enforcing Awards Across Borders: the Article V defenses through which evidentiary rulings are attacked.
• Section 1782 Discovery in Aid of Foreign Proceedings: Who Can Ask, What They Get, and What ZF Automotive Changed: the full history and the post-ZF landscape for U.S. discovery in aid of foreign proceedings.
• Confirming and Vacating Arbitration Awards: The Narrow Door of FAA Review: section 10(a)(3) and the deference courts give arbitral procedure.
• Investor-State Arbitration: Treaty Protections, Jurisdiction, and the Enforcement of Awards Against States: evidence and document production when a state is a party.
• Attorney-Client Privilege and Work Product for Businesses: Upjohn, In-House Counsel, and the Common Interest: the U.S. privilege doctrine that a tribunal may or may not apply.
• Expert Witnesses After the 2023 Amendment to Rule 702: Daubert, Disclosure, and Cross-Examination: the court-side contrast for expert gatekeeping.
• Cross-Examination Methods Compared: Pozner-Dodd, Younger's Ten Commandments, the Reptile, and the Reid Technique: technique to adapt for a hearing with no jury.
• Remote Video Depositions: Logistics, Remote Exhibits, Objections, and the Off-Camera Coaching Problem: remote-testimony safeguards that carry over to virtual hearings.

Related Guides

• Requesting and Resisting Document Production in International Arbitration: A Practical Guide: the step-by-step document production process for both sides.
• Running an International Arbitration: A Practical Guide: the whole case from clause to enforcement.
• Seeking or Opposing Section 1782 Discovery: A Practical Guide: when U.S. discovery is still available for proceedings abroad.
• Challenging or Enforcing an Arbitration Award: A Practical Guide: the post-award process in which evidentiary objections resurface.

Related Checklists

• Witness and Expert Evidence in International Arbitration Checklist: A Practical Checklist: phase-by-phase tasks for witness statements, expert reports, and hearings.
• International Arbitration Checklist: A Practical Checklist: the case-wide task list.
• Preparing a Privilege Log: A Practical Checklist: log mechanics that transfer to arbitral privilege claims.

Related Toolkits

• Arbitration Evidence Toolkit: Redfern Schedules, Witness Statement Templates, and Expert Protocols: the templates referred to throughout this article.
• International Arbitration Toolkit: Clauses, Procedural Orders, and Enforcement Petitions: a model clause, a PO1 outline, and an enforcement petition.
• Cross-Border Discovery Toolkit: 1782 Applications, Hague Requests, and Blocking Statute Analyses: forms for evidence located abroad.
• Treaty Arbitration Toolkit: Notices of Dispute, Jurisdictional Objections, and Enforcement Strategy: papers for investor-state cases.