Evidence admissibility in arbitration plays a critical role, often determining the outcome of disputes. Yet, deciding what evidence is accepted and what isn’t introduces its own challenges. Courts usually follow established protocols when assessing evidence, but arbitration, influenced by different legal cultures, procedural rules, and party agreements, has a distinct approach. This flexibility is both an advantage and a challenge. Businesses must grapple with this unique dynamic to ensure they present their cases effectively and, in doing so, steer clear of potential pitfalls. With the proper understanding, companies can turn these challenges into opportunities, ensuring the evidence they rely on stands firm and resonates with the arbitrator.

Basic Concepts of Admissibility

The term “admissibility” often surfaces when discussing evidence. Simply put, admissibility determines if an arbitrator can consider a particular piece of evidence when deciding the case. Not every document or piece of information holds equal standing; only those deemed admissible play a role in the arbitration’s outcome.

Adjacent to admissibility are the concepts of “relevance” and “materiality”.

“Relevance” examines the direct link between the evidence and the issues under discussion. If a piece of information fails to contribute to the dispute or doesn’t support a party’s position, it is labelled irrelevant. In practical terms, relevance answers the question: Does this evidence contribute to the case?

“Materiality”, however, goes a step further by assessing the significance of evidence. While evidence might have a connection to the case (making it relevant), it doesn’t always possess the necessary importance to influence the final decision.

Therefore, parties must ensure their evidence is admissible, relevant, and material in arbitration. Recognising these distinctions equips parties to present their case more efficiently and persuasively.

Determinants of Admissibility in Arbitration

The arbitration agreement often serves as the initial source for evidence guidelines. Through this agreement, parties can define explicit rules or outline criteria for what they deem as acceptable evidence, setting a clear stage from the beginning.

The procedural rules chosen by the parties also play a central role. Various arbitration institutions prescribe their distinct set of rules regarding evidence. While some may be expansive in their approach, others might restrict the scope. Hence, the chosen procedural rules can directly shape the type of evidence permitted.

The lex arbitri, the law that governs the arbitration process, further dictates the parameters of evidence admissibility. As it forms the legal backbone of the arbitration, it can offer clear markers on the admissibility criteria, guiding parties on the evidence presentation. For instance: 

    • Documentary Evidence: Some jurisdictions may necessitate specific authentication forms, especially for foreign documents.
    • Electronic Evidence: As reliance on digital communication grows, particular jurisdictions have established guidelines for admitting digital records and emails.
    • Witness Testimonies: In some jurisdictions, strict guidelines might exist on witness qualifications and the weight given to their testimonies.
    • Public Policy Considerations: Occasionally, evidence contradicting a jurisdiction’s public policy might be excluded, even if it’s otherwise relevant.

Despite these outlined standards, the arbitral tribunal retains a notable degree of autonomy. They have the discretion to decide on the admissibility of evidence, factoring in its relevance and alignment with the procedural rules. This underlines the importance of presenting evidence that is both robust and relevant.

On a broader scale, the International Bar Association’s (IBA) Rules on the Taking of Evidence in International Arbitration provide consistent guidelines for managing evidence in international contexts. Specifically, Article 9 outlines the criteria for assessing admissibility, relevance, and weight of evidence, placing the responsibility squarely on the shoulders of the Arbitral Tribunal. While not mandatory, these rules are an invaluable reference, particularly in cross-border disputes, highlighting reasons an arbitrator might exclude evidence, such as irrelevance or legal privilege. 

Understanding these key determinants equips parties to approach arbitration efficiently, enhancing their prospects for a successful resolution.

Common Grounds for Excluding Evidence

1. Relevance and Materiality: Evidence in arbitration must satisfy two primary criteria: relevance and materiality. Relevant evidence connects logically to the disputed matters, while material evidence holds significant value in proving specific facts. If evidence doesn’t directly support a party’s claim or defence, arbitrators may exclude it to maintain focus and efficiency.

2. Privilege: Certain communications enjoy protection from disclosure due to privilege. The nature and scope of privileges can differ across jurisdictions, but a few are widely recognised: 

    • Legal Professional Privilege: Ensures open communication between lawyers and clients by safeguarding their exchanges.
    • Without Prejudice Privilege: Promotes transparent settlement discussions by protecting their content.
    • Common Interest Privilege: Defends shared communications between parties with mutual legal interests.

Parties must identify and correctly apply these privileges, preventing inadvertent disclosures and preserving essential rights.

3. Confidentiality: One of arbitration’s distinct advantages is its confidentiality. Yet, this can sometimes pose challenges when admitting evidence. If disclosing evidence could breach confidentiality agreements, parties must weigh the value of that evidence against potential repercussions. Techniques such as redaction or anonymised versions can offer a middle ground, allowing for evidence admission without compromising confidentiality.

 4. Hearsay: While arbitration tends to be more accommodating of hearsay than traditional courts, it is crucial to approach such evidence cautiously. Hearsay, being information not directly witnessed by its presenter, can be less reliable. Arbitrators, while permitting hearsay, will often scrutinise its credibility, especially if unsupported by direct evidence.

5. Public Policy Considerations: Sometimes, broader societal interests can prevent the admission of specific evidence. If introducing certain evidence compromises a jurisdiction’s public values or legal principles, it may be set aside. For instance, evidence obtained through unlawful methods might be rejected to deter such activities.

Awareness of these grounds for exclusion assists parties in preparing comprehensive and compelling presentations, paving the way for more streamlined arbitration proceedings.

Practical Steps for Ensuring Evidence Admissibility

1. Preliminary Review: Start with a comprehensive assessment of the evidence. This early scrutiny helps identify elements of relevance and materiality and highlights potential issues that might challenge admissibility later.

2. Engage in Consultations: Some evidence might sit in grey areas, necessitating expert insight. Engaging with specialists, whether for electronic evidence interpretation or complexities concerning privileges, can clarify the standing of such evidence. Their guidance can be the difference between acceptance and rejection.

3. Proactive Engagement with Opposing Parties: Early dialogue with the other party can preclude many evidentiary disputes. Reaching preliminary agreements on specific evidence can expedite proceedings and foster a constructive environment conducive to resolution.

4. Adherence to Procedural Rules and Agreements: Consistent compliance with the governing procedural rules, whether determined by an institution or agreed upon by the parties, is non-negotiable. Ensuring all evidence aligns with these rules supports its admissibility and establishes a party’s credibility.

5. Presentation Techniques: The clarity and organisation of evidence presentation can affect its reception. Offering evidence in a structured manner, using tools like summaries for extensive documents or visual aids for technical data, ensures arbitrators can readily discern its significance.

By adopting these pragmatic steps, parties enhance the likelihood of their evidence being admitted, thus strengthening their position in the arbitration process.

Potential Pitfalls and How to Avoid Them

Minor errors can have major implications when submitting evidence in arbitration. Below are frequent missteps and practical solutions to address them:

1. Overburdening with Evidence: It’s a common misconception that a voluminous submission strengthens a case. However, verbosity can obscure vital points amid redundant information.

Solution: Focus on presenting compelling evidence that directly supports your arguments.

2. Overlooking Jurisdictional Differences: Arbitration rules can differ markedly across jurisdictions. Neglecting these distinctions may lead to the submission of non-compliant evidence.

 Solution: Thoroughly familiarise yourself with the evidentiary guidelines of the applicable jurisdiction or arbitral institution.

3. Failing to Contest Questionable Evidence: Some parties overlook opportunities to challenge the admissibility of their opponent’s evidence, potentially weakening their position.

Solution: Maintain vigilance. Systematically review opposing evidence and assertively challenge any that seem out of line.

4. Misapplying Privileges: Occasionally, parties may assert privileges without adequate justification, undermining their credibility.

 Solution: Ensure that every claim of privilege stands on firm legal ground. When uncertain, seek expert advice.

By being attentive to these areas and taking proactive measures, parties can bolster the admissibility and impact of their evidence in arbitration.

Special Considerations for Digital Evidence

The digital revolution has ushered in a new era where electronic information plays a significant role in arbitration. Digital communications are frequently front and centre in many disputes, from emails to instant messages.

However, this shift presents unique challenges. E-discovery, the act of identifying and collecting electronic data, can be an extensive endeavour. With vast amounts of data stored across various platforms, identifying relevant information requires strategic planning and precision.

The admissibility of digital evidence brings its own set of issues. Since electronic files can be altered easily, establishing their authenticity and integrity is paramount. Parties must offer clear proof that the electronic data remains unchanged from its initial state. For instance, digital signatures verify a sender’s identity, ensuring a document’s origin. Hash values, essentially unique digital ‘fingerprints’ for files, can confirm that no changes have occurred since the value was generated. Timestamps provide a date and time stamp, attesting to when a file was created or modified. Moreover, a well-documented chain of custody can help validate that the data remains untouched during storage and transfer.

Finally, arbitrators, who might lean towards traditional forms of evidence, could benefit from additional clarity when evaluating digital records. As the importance of electronic information continues to grow, parties must stay abreast of best practices in managing and presenting digital evidence, ensuring a more streamlined and effective arbitration process.

Final Thoughts

Admissibility in arbitration plays a crucial role, often determining the direction and outcome of disputes. With the increasing significance of digital evidence, the stakes are higher than ever. A slight oversight in evidence submission can significantly affect the resolution in favour or against a party.

Understanding and abiding by evidence rules is a strategic necessity for businesses of all scales. Ensuring thorough evidence gathering and proper presentation is vital to success. Staying updated with current best practices simplifies the arbitration process and positions businesses for optimal outcomes.


The insights presented in this blog post aim to furnish readers with a broad understanding of arbitration within the context of global business. This material does not purport to provide legal advice, but rather serves as an informative resource. Specific decisions concerning arbitration and its relevance should always be made in consultation with qualified legal experts. Given the intricate variations and legal implications of arbitration across different jurisdictions, it is paramount to collaborate with legal professionals well-acquainted with the precise legal framework pertinent to your circumstances.

If you find this content valuable and have further questions, or if you require guidance on the detailed aspects of arbitration, please feel free to reach out to our dedicated team at arbitration@broderickbozimo.com. We stand ready to guide you through these processes and address any areas of concern.

Isaiah Bozimo

Isaiah Bozimo


Afolasade Banjo

Afolasade Banjo


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