Arbitrator independence and impartiality form the cornerstone of a legitimate arbitral process. Under section 19 of the Thai Arbitration Act B.E. 2545 (2002), prospective arbitrators must disclose circumstances likely to give rise to justifiable doubts as to their impartiality or independence, and existing arbitrators must do so throughout proceedings. This mirrors article 12 of the UNCITRAL Model Law. Yet despite this clear mandate, practical implementation varies significantly across Thailand’s arbitration landscape.
Background
Thailand’s two principal arbitration institutions, the Thai Arbitration Institute (TAI) and the Thailand Arbitration Center (THAC), both maintain procedures for addressing arbitrator challenges and require compliance with the statutory disclosure obligation. Under both sets of rules, any party wishing to challenge an arbitrator must submit a challenge application within fifteen days of becoming aware of the relevant facts, and a committee is appointed to consider the matter on a case-by-case basis. The TAI additionally prescribes its Code of Ethics and Conduct for Arbitrators to further emphasize the expectation of impartiality and transparency.
However, Thailand’s arbitration ecosystem extends well beyond the TAI and THAC. Several sector-specific institutions also administer arbitral proceedings, including the Thai Commercial Arbitration Office under the Board of Trade of Thailand, the Arbitration Centre of the Office of the Insurance Commission, the Arbitration Centre of the Securities and Exchange Commission, the Office for the Prevention and Resolution of Disputes regarding Intellectual Property, and the Arbitration Centre of the Thai General Insurance Association. These institutions each operate under their own procedural rules, which were developed to serve particular industries and dispute profiles. The procedural mechanisms for securing and documenting an independence declaration are not uniformly established across these forums.
Consequences of Procedural Inconsistency
This creates a notable gap. Not all arbitration bodies have a formalized procedure requiring written independence statements before proceedings commence. Some tribunals proceed directly to the first procedural hearing without the arbitrator having made any formal declaration. This can deprive a party of the opportunity to assess potential conflicts at the earliest stage, potentially giving rise to grounds for setting aside an award under section 40 of the Arbitration Act.
Thai courts have taken an increasingly serious view of disclosure failures. In Supreme Court Decision No. 3542/2561, the court set aside an arbitral award because the presiding arbitrator failed to disclose his involvement as defense counsel in a prior, related insurance matter, despite neither party in the earlier case being a party to the arbitration in question. The court held that this nondisclosure gave rise to justifiable doubts under section 19 and rendered the enforcement of the award contrary to public policy. This decision underscores that Thai courts expect rigorous compliance with the disclosure obligation.
Given these risks, arbitration institutions in Thailand should take proactive compliance steps. Arbitrators should understand that requests for independence declarations are not a challenge to their integrity but are designed to protect the legitimacy of proceedings, the enforceability of awards, and the integrity of the arbitral forum itself. If no formalized process exists, parties should request that written confirmations of independence and impartiality be placed on record before substantive proceedings commence.
This article was first published in the May 2026 Thailand edition of The Legal Industry Reviews, an international platform that publishes news and applied law updates from industry-leading law firms worldwide. To browse the latest complete issue, please visit The Legal Industry Reviews website.
