- 02-Nov-2025
- public international law
The standard of proof in international arbitration typically differs from that in national courts. While courts often rely on strict standards (such as beyond a reasonable doubt in criminal cases or preponderance of the evidence in civil cases), international arbitration tends to follow a more flexible approach. The standard of proof refers to the degree of certainty required to prove a claim. In international arbitration, the standard is generally closer to the balance of probabilities (also called preponderance of the evidence), but the tribunal has the discretion to adjust the standard based on the nature of the case.
The standard of proof in most international arbitration cases is the balance of probabilities. This means that a party must prove that its version of events is more likely than not to be true.
In simple terms, the party bearing the burden of proof must establish that their claim or defense is more probable than not, i.e., the evidence supporting their argument outweighs the evidence against it.
Example: In a contract dispute, if one party claims that a breach occurred, they need to show that it is more likely than not that the breach happened, based on the evidence presented (emails, contracts, witness statements).
Unlike national courts, where the standard of proof can be more rigid, international arbitration offers greater flexibility. The arbitral tribunal has significant discretion in determining the standard of proof based on the nature of the dispute.
For instance, in cases involving highly technical or complex issues, the tribunal may consider a higher standard of proof for certain aspects of the case, especially if the consequences of the dispute are substantial.
Example: In a dispute over a breach of intellectual property rights, the tribunal might expect more robust evidence (such as expert reports) to meet the balance of probabilities standard.
International arbitration generally follows a civil standard of proof, which is typically lower than the criminal standard of proof (which requires proof beyond a reasonable doubt).
The civil standard requires that a party's evidence be more persuasive than that of the opposing party. However, the tribunal can adjust this standard based on the nature of the claims.
Example: In a construction dispute, the claimant does not need to prove their case beyond any doubt; they must only show that their version of events is more probable than not.
The burden of proof typically lies with the party making a claim or assertion. The claimant, for instance, has the responsibility to prove the facts underlying their claim. In some cases, if the defendant raises a counterclaim, they will also bear the burden of proof for their own assertions.
The burden of proof is generally not as rigidly defined in arbitration as it is in court, and the tribunal has the discretion to assess how much weight to give to the evidence presented by each party.
Example: If a party claims damages for breach of contract, they must show evidence of the breach and the resultant harm. If the opposing party denies the breach, they may not be required to disprove the claim but rather to raise doubts as to its validity.
Arbitral tribunals have discretion in determining the standard of proof based on procedural fairness and the judicial economy of the arbitration process. The tribunal's goal is to arrive at a fair and efficient resolution while ensuring that the standards of proof reflect the specific nature of the dispute.
Example: In a high-value commercial dispute, the tribunal might apply a higher standard of proof for claims involving significant financial losses but might relax the standard for less material claims, ensuring a balance between fairness and efficiency.
The institutional rules governing the arbitration (such as ICC, LCIA, SIAC, or others) may provide some guidance on how evidence should be evaluated, although the final decision remains with the tribunal.
The parties can also agree on a specific standard of proof, which the tribunal may follow as long as it is not in conflict with mandatory principles of fairness and due process.
Example: Under the ICC Arbitration Rules, the tribunal is expected to assess the evidence in accordance with the rules of procedure and fairness, but the standard of proof is ultimately at the tribunal's discretion.
In national court systems, the standard of proof is usually more formalized:
International arbitration, being more flexible, allows the tribunal to assess and apply the standard of proof that best suits the nature of the dispute. This flexibility is a key characteristic of arbitration.
Tribunals in arbitration have more discretion to determine the sufficiency of evidence and how to weigh it. They are not bound by formal rules of evidence like national courts, which allows for a more pragmatic and flexible approach to fact-finding.
Example: While a national court might exclude certain types of evidence (e.g., hearsay), an arbitral tribunal might admit such evidence if it is deemed relevant and reliable.
In an international arbitration between Logistics Corp. (the claimant) and Transporters Inc. (the respondent), Logistics Corp. claims that Transporters Inc. failed to deliver goods under a supply agreement.
Logistics Corp. submits email correspondence, the supply contract, and witness statements indicating that the goods were not delivered on time, leading to financial losses.
Transporters Inc. argues that the delay was due to an unforeseeable strike, submitting documents and witness statements that support their defense.
The tribunal assesses whether the evidence presented by Logistics Corp. meets the balance of probabilities standard. Given the documents and testimony, the tribunal must decide which version of the events is more likely to be true.
If the tribunal finds that Logistics Corp.’s evidence is more compelling (more likely than not), the claim for breach of contract is upheld. However, if the tribunal believes the delay was indeed caused by an unforeseeable strike and supported by credible evidence, the claim may be dismissed.
In international arbitration, the standard of proof is generally the balance of probabilities, meaning that the party with the burden of proof must show that their claims are more likely to be true than not. However, arbitration tribunals have the discretion to adjust this standard based on the nature of the case and the specific circumstances. This flexibility allows tribunals to efficiently manage cases while ensuring fairness and due process.
Answer By Law4u Team
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