International arbitration is a popular method for resolving cross-border commercial disputes. A crucial aspect of any arbitration proceeding is the standard of proof required to establish the claims and defence in a case.

This article examines the concept of the standard of proof in international arbitration, the different approaches adopted by civil law and common law jurisdictions, and the various factors that can influence the applicable standard of proof. By understanding the nuances of the standard of proof in international arbitration, parties can better navigate the arbitration process and maximize their chances of success.

What Is The Standard of Proof in International Arbitration

The standard of proof refers to the level of certainty and the degree of evidence necessary to establish a claim or defence in a legal proceeding. In international arbitration, the standard of proof determines the quantity of evidence required to prove an issue or case. It is a fundamental aspect of the arbitral process, as it influences the weight given to the evidence presented by the parties.

In general, there are two primary approaches to determining the standard of proof in international arbitration: civil law and common law. The applicable standard of proof can vary depending on the chosen system of law, the nature of the allegations, and the procedural phase of the arbitration.

Civil Law Jurisdictions

In civil law jurisdictions, the standard of proof is generally based on the “inner conviction” or “free evaluation of evidence” standard. This means that the judges or arbitrators must be convinced of the truth of a claim or defence based on their assessment of the evidence presented. There is no fixed or codified standard of proof in civil law systems, and judges have significant discretion in evaluating the evidence and determining its weight.

Common Law Jurisdictions

In common law jurisdictions, the standard of proof differs based on whether the dispute is a civil or criminal matter. For civil disputes, the standard of proof is typically the “preponderance of the evidence” or “balance of probabilities” standard, which requires that there be greater evidence in favour of a claim than against it. In other words, a claim must be more likely than not to be true. For criminal matters, the standard of proof is more stringent, requiring that a claim be proven “beyond a reasonable doubt.”

Factors Influencing the Standard of Proof in International Arbitration

In practice, the applicable standard of proof in international arbitration can be influenced by various factors, including the procedural phase of the arbitration, the nature of the allegations, whether the allegations are contested, and the set of laws and rules that may apply to or influence the substantive and procedural questions in the arbitration.

Procedural Phase of Arbitration

The applicable standard of proof can differ depending on the procedural phase of the arbitration. For example, a lower “prima facie” standard of proof may be applied to claims regarding interim measures, jurisdictional issues, or facts that are objectively difficult to prove. Conversely, a higher standard of proof may be required for consent-related issues or other matters that are particularly delicate.

Interim Measures

In the context of interim measures, international arbitration rules, such as the UNCITRAL Model Law, often require a “reasonable possibility” that the requesting party will succeed on the merits of the claim. This “prima facie” standard is lower than the “preponderance of the evidence” standard and is intended to filter out frivolous requests for interim measures.

Jurisdictional Issues

For jurisdictional matters, arbitrators and arbitral institutions may apply the “prima facie” standard, meaning that the parties must be able to demonstrate, on a preliminary basis, that their claims fall within the scope of the arbitration agreement.

Nature of the Allegations

The nature of the allegations in an arbitration can also influence the standard of proof. For example, claims involving fraud, corruption, or bad faith may require a higher standard of proof, such as “clear and convincing evidence.” However, arbitral practice in this area is not uniform, and some tribunals may still apply the “preponderance of the evidence” standard for such claims.

Contested vs. Uncontested Allegations

Whether allegations are contested or uncontested can also impact the standard of proof in international arbitration. In cases where one party is absent or has defaulted, the tribunal may still apply the “preponderance of the evidence” standard, but the threshold for meeting this standard may be lower due to the lack of opposing evidence.

Applicable Laws and Rules

The set of laws and rules that govern the arbitration dispute can also influence the standard of proof. For example, some arbitration rules and conventions, like the ICSID Convention, contain specific provisions addressing the standard of proof for certain actions, such as annulment or disqualification of arbitrators. In such cases, the standard of proof may be explicitly stated or may be subject to interpretation by the arbitral tribunal.

The Default Standard of Proof in International Arbitration

Despite the variations and factors influencing the standard of proof in international arbitration, it is widely accepted that the default standard of proof for most issues is the “preponderance of the evidence” standard. This standard is commonly applied to breaches of standards of protection, defences, claims for damages, and stays of enforcement.

However, other standards of proof may be deemed applicable by arbitrators based on the specific circumstances of the case. For instance, a heightened “clear and convincing evidence” standard may be applied to consent-related issues or other sensitive matters, while a lower “prima facie” standard may be applied to claims involving interim measures or jurisdictional issues.