Introduction

In commercial arbitration, the tribunal is typically composed of either a sole arbitrator or a panel of three. Most arbitration frameworks and institutional rules historically favored three arbitrators to promote impartiality and avoid deadlock in complex disputes. Several modern developments now influence the choice more strongly – including expedited procedures, emergency arbitrators, and cost-efficiency reforms.

1. General Principles on Tribunal Size

Party Autonomy

Parties remain free to determine the number of arbitrators in their arbitration clause. One arbitrator is common for lower-value or simpler disputes, while three are preferred for complex, high-value, or multi-party matters.

Default Rules

If the parties do not specify the number of arbitrators:

• UNCITRAL Model Law (Art. 10(2))
  Default: three arbitrators.
• UNCITRAL Arbitration Rules (Art. 5)
  Same default: three arbitrators.

Institutional Rules

• LCIA Rules (2020)
  Default: one arbitrator, unless the LCIA Court determines that three are appropriate.
• ICC Rules (2021)
  Default: three arbitrators, but the ICC Court may appoint a sole arbitrator for lower-value cases or under the Expedited Procedure Rules (EPR), which apply by default to disputes ≤ USD 3 million.
• ICDR Rules
  Default: one arbitrator, unless the parties agree otherwise or the ICDR determines three are appropriate.
• SIAC Rules (2016)
  Default: one arbitrator, unless the case warrants three.

Why Two Arbitrators Are Avoided

Tribunals with two arbitrators risk deadlock and are therefore avoided.

2. Multi-Party Arbitration Considerations

Equal Participation in Appointments

All parties must have a fair opportunity to participate in selecting arbitrators.

Joint Nominations

Where multiple claimants or respondents are aligned, they may be required to jointly nominate an arbitrator.

Institutional Solutions

• ICC Rules (Art. 12(8))
  If parties cannot agree on joint nominations, the ICC Court may appoint all members of the tribunal to preserve balance.
• LCIA Rules
  Provide similar mechanisms to ensure fairness in multi-party appointments.
• SIAC & HKIAC
  Both institutions have robust multi-party appointment mechanisms, often empowering the institution to appoint the entire tribunal if joint nominations fail.

Efficiency vs. Fairness

Multi-party arbitration must balance efficiency with fairness, and three arbitrators are often chosen to safeguard impartiality.

3. Jurisdiction-Specific Notes (South Africa, UK, Singapore)

South Africa

• International Arbitration Act 2017 adopts the UNCITRAL Model Law.
  Default: three arbitrators (unless parties agree otherwise).
• AFSA International Rules
  Default: one arbitrator, unless the parties specify three.

England (Arbitration Act 1996)

• Default: one arbitrator, unless the parties agree otherwise.

Singapore (IAA + SIAC Rules)

• SIAC default: one arbitrator, unless complexity or value warrants three.

4. Modern Procedural Developments Affecting Tribunal Size

Expedited Procedures

Many institutions now default to a sole arbitrator for disputes below a monetary threshold:

• ICC: USD 3 million
• SIAC: SGD 6 million
• HKIAC: HKD 25 million

Emergency Arbitrators

Emergency arbitrator provisions do not replace the main tribunal but influence drafting strategy. Parties may choose a sole arbitrator for speed, knowing emergency relief is available separately.

Fast-Track Arbitration

Fast-track or documents-only procedures almost always use one arbitrator.

5. Practical Drafting Guidance

Model Clause – Sole Arbitrator

“The tribunal shall consist of a sole arbitrator appointed in accordance with the [Institution] Rules.”

Use for:

• Low-value contracts
• Time-sensitive disputes
• Situations where cost efficiency is critical

Model Clause – Three Arbitrators

“The tribunal shall consist of three arbitrators. Each party shall nominate one arbitrator, and the two nominated arbitrators shall nominate the presiding arbitrator.”

Use for:

• High-value or technically complex disputes
• Multi-party arrangements
• Situations where perceived neutrality is essential

Model Clause – Multi-Party

“Where there are multiple claimants or respondents, the aligned parties shall jointly nominate an arbitrator. If they fail to do so, the appointing authority shall appoint all members of the tribunal.”

Prevents pathological clauses and ensures enforceability.

6. Comparison Table

7. Risks & Trade-offs

• Cost & Time: Three arbitrators increase costs and length of proceedings.
• Fairness Concerns: Multi-party appointments can create legitimacy concerns if not managed properly.
• Institutional Intervention: Institutions or courts may step in when parties cannot agree, reducing autonomy but ensuring fairness.

Additional considerations:

• Risk of Pathological Clauses: Clauses specifying two arbitrators or unclear appointment mechanics can render the clause unworkable.
• Procedural Flexibility: Sole arbitrators can move faster and reduce procedural complexity.

8. Practical Takeaway

Always specify the number of arbitrators in the arbitration clause – one for smaller or time-sensitive contracts, three for complex or multi-party matters.

In multi-party scenarios, anticipate institutional rules stepping in to ensure balanced appointments, as your note correctly states.

References and Further Information

• Trans-Lex.org. https://www.trans-lex.org/968915/_/number-of-arbitrators/
• https://academic.oup.com/oxford-law-pro/book/57649/chapter/469838231
• https://jurishift.com/multi-party-arbitration-procedures/

Disclaimer

This practice note provides general information on commercial arbitration and is not legal advice. For specific cases, consult a qualified arbitration professional or legal counsel.