Arbitrator Conduct: Common Standards Across the Major Institutional Codes
Arbitrator ethics is not governed by a single, universal instrument. Instead, it is shaped by a body of overlapping codes and guidelines issued by different institutions: the IBA Guidelines on Conflicts of Interest in International Arbitration (2024), the ICSID/UNCITRAL Code of Conduct for Arbitrators in International Investment Dispute Resolution (2023/2024), the ICC's Note to Parties and Arbitral Tribunals, the LCIA Arbitration Rules 2020, the SIAC Code of Ethics for an Arbitrator, the HKIAC Code of Ethical Conduct, the CIArb Code of Professional and Ethical Conduct for Members, and the AAA-ABA Code of Ethics for Arbitrators in Commercial Disputes (2004). These instruments differ in scope, drafting history and legal status, some are binding institutional rules, whereas others are non-binding soft law; but a comparison of their operative provisions shows a set of recurring standards. This article summarises those standards without endorsing one institution's formulation over another.
Each instrument requires an arbitrator to be independent and impartial at the time of appointment and to remain so for the duration of the proceeding. This is expressed as General Standard 1 of the IBA Guidelines, Article 3 of the ICSID/UNCITRAL Code, and in equivalent terms in the LCIA Rules (Article 5.3), the SIAC and HKIAC codes, and Canon I of the AAA-ABA Code. The obligation is generally understood to extend until the final award (including any correction or interpretation of it), rather than through any subsequent challenge or enforcement proceedings.
A recurring formulation across these instruments is that any doubt as to whether a fact or circumstance should be disclosed is to be resolved in favour of disclosure. This appears, in substantially similar language, in the IBA Guidelines (General Standard 3(d)), the ICC Note (paragraph 30), the ICSID/UNCITRAL Code (Article 11(5)), the LCIA framework, SIAC's Code and the AAA-ABA Code (Canon II(D)). Under each instrument, disclosure does not by itself establish a conflict of interest or a lack of independence; its function is to place relevant information before the parties so that they, or the relevant institution, may assess it.
The duty to disclose is not discharged by a single statement made at the outset of the appointment. The ICC Note, the ICSID/UNCITRAL Code, the LCIA Rules and the IBA Guidelines each treat disclosure as continuing throughout the arbitration, requiring supplementary disclosure as new facts arise or are discovered. Several instruments (the ICC Note and the ICSID/UNCITRAL Code in particular) also specify that the arbitrator is expected to make reasonable enquiries of personal and firm records, rather than disclose only what is recalled without enquiry.
Several codes address an arbitrator's capacity to conduct the proceeding properly, in addition to independence. SIAC's Code conditions acceptance of appointment on adequate knowledge of the language of the arbitration and sufficient time to attend to the case; the ICSID/UNCITRAL Code sets out a discrete “duty of diligence” (Article 5); and the ICC Note requires prospective arbitrators to disclose current caseload and availability. The AAA-ABA Code (Canon I(B)) similarly conditions acceptance on the arbitrator's competence and availability to complete the case.
Each instrument restricts communication between an arbitrator and one party in the absence of the other. The ICSID/UNCITRAL Code (Article 7) and the AAA-ABA Code (Canon III) set out the permitted exceptions in some detail – principally, pre-appointment enquiries as to availability, qualifications and the general nature of the dispute, and, in tripartite tribunals, limited communication concerning the selection of a presiding arbitrator. Outside these carve-outs, substantive communication with one party alone is not permitted under any of the instruments reviewed.
The ICSID/UNCITRAL Code, the HKIAC Code and the CIArb Code each require an arbitrator to maintain the confidentiality of the proceeding and of the tribunal's deliberations, and to refrain from using information obtained in the course of the arbitration for personal advantage. Under several instruments, aspects of this obligation continue after the arbitrator's role in the case has ended.
The codes that address remuneration (SIAC, the AAA-ABA Code, and to a lesser extent CIArb) require that fees be reasonable, disclosed to the parties (or channelled through the administering institution), and not the subject of unilateral arrangements between an arbitrator and one party.
The IBA Guidelines are distinct among these instruments in providing a structured framework – the Non-Waivable Red List, Waivable Red List, Orange List and Green List – for assessing categories of relationship and their consequences for disclosure and appointment. The 2024 revision extended this framework to address, among other matters, third-party funding, issue conflicts and social media connections. Other institutions do not adopt an equivalent taxonomy but apply comparable underlying tests (objective doubt as to impartiality or independence, assessed from the perspective of a reasonable third person, or of the parties).
Notwithstanding differences in drafting and institutional context, the instruments reviewed converge on a limited set of standards: continuing independence and impartiality, disclosure resolved in favour of transparency and treated as an ongoing obligation, adequate diligence and availability, restrictions on unilateral communication, confidentiality, and reasonable and transparent fee arrangements. Practitioners appointing or accepting appointment as arbitrators may find it useful to consult the applicable institutional rules directly, together with the IBA Guidelines where relevant, rather than relying on any single formulation summarised here.
This article is a comparative summary prepared for general informational purposes and does not constitute legal advice. It should be read together with, and does not substitute for, the official text of the instruments referenced: the IBA Guidelines on Conflicts of Interest in International Arbitration (2024), the ICSID/UNCITRAL Code of Conduct for Arbitrators (2023/2024), the ICC Note to Parties and Arbitral Tribunals (2026), the LCIA Arbitration Rules 2020, the SIAC Code of Ethics for an Arbitrator, the HKIAC Code of Ethical Conduct, the CIArb Code of Professional and Ethical Conduct for Members, and the AAA-ABA Code of Ethics for Arbitrators in Commercial Disputes (2004).