An undisclosed relationship, a private communication with one party or a failure to devote sufficient attention to proceedings may raise concerns about an arbitrator’s conduct. Assessing those concerns requires identifying the applicable obligations and the standard against which the conduct should be measured. In international arbitration, those standards are drawn from several sources rather than a single ethical code.
The Law of the Seat Is Generally the Starting Point
In international arbitration, the starting point is generally the law of the seat, which may impose mandatory obligations upon arbitrators.
For example, Section 33 of the English Arbitration Act requires the tribunal to act fairly and impartially, give each party a reasonable opportunity to present its case and answer its opponent, and adopt procedures avoiding unnecessary delay or expense.[1] Section 23A, introduced by the Arbitration Act 2025, also imposes a mandatory disclosure obligation on prospective and appointed arbitrators in relation to circumstances that might reasonably give rise to justifiable doubts as to their impartiality.[2]
Selecting institutional rules or referring to an international ethical code does not dispense with the need to consider the applicable national statute.
Arbitration Rules Can Impose Their Own Ethical Obligations
The applicable arbitration rules are another important source of arbitrators’ ethical obligations.
Under the 2026 ICC Arbitration Rules, every arbitrator must remain impartial and independent. Article 12 requires disclosure before appointment and throughout the proceedings, while Article 23 requires fair, impartial and efficient conduct of the arbitration.[3]
The 2020 LCIA Arbitration Rules similarly require independence, impartiality and continuing disclosure.[4] They also require candidates to confirm that they can devote sufficient time, diligence and industry to the case.[5] Article 5.3 prohibits arbitrators from acting as a party’s advocate or authorised representative or advising a party on the dispute or the conduct or outcome of arbitration.[6]
An arbitral institution may also incorporate a separate ethical code. Rule 20.1 of the 2025 SIAC Arbitration Rules requires arbitrators to conduct themselves in accordance with the Rules, the SIAC Code of Ethics and applicable Practice Notes.[7] The SIAC Court may remove an arbitrator for failure to comply with these instruments.[8] Therefore, a code that would otherwise require a separate basis of application can become obligatory through the arbitration rules themselves.
The IBA Instruments: Guidance Unless Given Binding Effect
The International Bar Association (“IBA”) has issued two important instruments addressing arbitrator ethics.
The largely forgotten 1987 IBA Rules of Ethics for International Arbitrators (“Rules of Ethics”) address a broad range of conduct, including acceptance of appointments, duty of disclosure, communications with parties, fees, diligence, settlement proposals and confidentiality of deliberations.[9] The Introductory Note explains that the Rules are intended as guidelines rather than rigid rules and are not directly binding on arbitrators or parties unless adopted by agreement.[10]
The 2024 IBA Guidelines on Conflicts of Interest in International Arbitration (“IBA Conflict Guidelines”) focus specifically on impartiality, independence and disclosure.[11] They establish General Standards, supplemented by a traffic-light system of red, orange and green lists. The Red List distinguishes between conflicts that cannot be waived and those that may be waived with the parties’ fully informed, express consent. The Orange List identifies circumstances requiring disclosure, while the Green List covers situations that ordinarily require none.[12]
The 2024 IBA Conflict Guidelines do not override applicable national laws, arbitral rules, codes of conduct or other binding instruments.[13] They supersede the 1987 Rules of Ethics on overlapping topics, while the earlier Rules remain relevant to other subjects.[14]
Professional and Institutional Codes of Ethics
Membership of a professional body may create additional ethical obligations.
Arbitrators who are qualified lawyers may remain subject to the professional conduct rules of the bar associations or other legal regulators to which they belong, even when acting as arbitrators rather than as counsel. The precise scope of these obligations depends on the applicable jurisdiction, and breaches may give rise to professional disciplinary consequences independently of any challenge to the arbitrator or the award.
Further, the Chartered Institute of Arbitrators’ Code of Professional and Ethical Conduct for Members (“CIArb Code”) applies to its members acting or seeking to act as neutrals, whether or not they were appointed by the Institute.[15] Beyond conflicts of interest, it addresses competence, inappropriate delegation of decision-making, delay, confidential information and reasonable fees.[16]
The CIArb Code nevertheless states that it does not form part of the rules of a dispute resolution process, override the applicable rules or laws, or provide grounds for judicial review or other legal action.[17]
The 2004 AAA/ABA Code of Ethics for Arbitrators in Commercial Disputes provides another example. Its Preamble clarifies that, although the Code may establish ethical standards for arbitrators on an institution’s panel, it does not automatically become part of that institution’s arbitration rules unless those rules so provide.[18]
Ethical Obligations in Investment Arbitration
In investment arbitration, arbitrators’ ethical obligations may arise from the applicable investment treaty, arbitration rules and codes of conduct governing the proceedings.
Under the ICSID Convention, Articles 14(1) and 40(2) prescribe arbitrator qualifications, including high moral character and the capacity to exercise independent judgment. Article 57 provides for disqualification where an arbitrator manifestly lacks the required qualities.[19] The Convention also supplies its own annulment framework, rather than permitting awards to be set aside by national courts at the seat.[20]
The 2023 UNCITRAL Code of Conduct for Arbitrators in International Investment Dispute Resolution (“UNCITRAL Code”) provides a more detailed ethical framework. The Code addresses, among other matters, concurrent and subsequent professional roles, diligence, ex parte communications and confidentiality. Article 4 restricts arbitrators from also acting as counsel or expert witnesses in specified circumstances, subject to exceptions. Article 12(3) leaves challenges, disqualification, sanctions and other remedies to the instrument of consent or the applicable rules.[21]
The binding effect of the UNCITRAL Code in a particular arbitration depends on the applicable legal framework.[22] Article 2(1) also permits its application by agreement to other dispute-resolution proceedings.[23]
Consequences of Breaching Ethical Obligations
A breach of an ethical obligation does not automatically justify an arbitrator’s disqualification. Whether disqualification is warranted depends on the nature of the breach and the grounds for challenge or removal under the applicable law and arbitration rules.[24]
In Halliburton Company v Chubb Bermuda Insurance Ltd, the UK Supreme Court held that an arbitrator had breached his disclosure duty by failing to disclose an appointment in another potentially overlapping arbitration involving a common party. Nevertheless, on the facts known at the date of the first-instance removal hearing, the Court found no real possibility of bias and dismissed the appeal.[25]
General Standard 3(g) of the 2024 IBA Conflict Guidelines similarly provides that a failure to disclose does not necessarily establish a conflict of interest or justify disqualification. The circumstances must be assessed against the applicable legal standard rather than treating non-disclosure alone as decisive.[26]
Some arbitration rules expressly provide for the removal of arbitrators for breach of ethical obligations. Rule 29.1 of the 2025 SIAC Arbitration Rules, for example, allows the SIAC Court to remove an arbitrator who fails to comply with the Rules, the SIAC Code of Ethics or applicable Practice Notes, after considering the views of the parties and arbitrators.[27]
Parties seeking to challenge an arbitrator must also comply with the applicable procedure and time limits. Under the standard procedure in the 2026 ICC Arbitration Rules, a challenge must be submitted in writing to the Secretariat within 30 days of receipt of notification of the arbitrator’s appointment or confirmation, or within 30 days of learning the relevant facts, whichever is later.[28]
Finally, an ethical breach does not automatically invalidate an arbitral award or prevent its enforcement. Under the New York Convention, recognition and enforcement may be refused on specified grounds, including where a party was unable to present its case, the composition of the tribunal or the arbitral procedure did not comply with the parties’ agreement or, failing such agreement, the law of the country where the arbitration took place, or enforcement would be contrary to the public policy of the enforcing State.[29]
Conclusion
There is no single, universally applicable code of ethics for arbitrators. Their obligations may arise from the applicable law, arbitration rules, codes adopted by the parties and, where relevant, professional obligations. International guidelines, including the IBA Guidelines, can provide useful guidance but are not automatically binding.
Equally, an ethical breach does not necessarily justify disqualification or affect the validity or enforceability of an award. The governing legal framework determines both the obligations imposed on arbitrators and the consequences of non-compliance.
[1] English Arbitration Act, s. 33.
[2] Id. s. 23A and Sch. 1; Arbitration Act 2025, ss. 2(3) and 17(4).
[3] 2026 ICC Arbitration Rules, Arts. 12(1)-(3), 23(1), 23(4).
[4] 2020 LCIA Arbitration Rules, Arts. 5.3-5.5.
[5] Id. Art. 5.4(ii).
[6] Id. Art. 5.3.
[7] 2025 SIAC Arbitration Rules, R. 20.1.
[8] Id. R. 29.1(a).
[9] 1987 IBA Rules of Ethics for Intl. Arbitrators, Arts. 2-9.
[10] Id. Introductory Note.
[11] 2024 IBA Guidelines on Conflicts of Interest in Intl. Arbitration, Introduction, paras. 1-3 and pt. I.
[12] Id. General Standards 3(a), 4(b)-(c) and pt. II, paras. 2-3 and 7.
[13] Id. Introduction, para. 6.
[14] Id. Introduction, para. 8.
[15] CIArb Code of Professional and Ethical Conduct for Members, Introduction and pt. 2, Introduction.
[16] Id. pt. 2, Rs. 4-9.
[17] Id. pt. 2, Introduction.
[18] 2004 AAA/ABA Code of Ethics for Arbitrators in Comm. Disputes, Preamble.
[19] Convention on the Settlement of Investment Disputes between States and Nationals of Other States, opened for signature 18 March 1965, Arts. 14(1), 40(2), 57.
[20] Id. Arts. 52, 53(1).
[21] 2023 UNCITRAL Code of Conduct for Arbitrators in Intl. Investment Dispute Resolution, Arts. 4-8, 12(3).
[22] Id. Art. 2; Commentary to the UNCITRAL Code of Conduct for Arbitrators in Intl. Investment Dispute Resolution, paras. 15-16.
[23] UNCITRAL Code of Conduct, Art. 2(1).
[24] IBA Conflict Guidelines, General Standard 3(g); UNCITRAL Code of Conduct, Art. 12(3).
[25] Halliburton Company v Chubb Bermuda Insurance Ltd [2020] UKSC 48 [145]-[150], [155]-[158].
[26] IBA Conflict Guidelines, General Standard 3(g).
[27] 2025 SIAC Arbitration Rules, R. 29.1(a).
[28] 2026 ICC Arbitration Rules, Art. 15(1)-(2).
[29] Convention on the Recognition and Enforcement of Foreign Arbitral Awards, opened for signature 10 June 1958, Art. V(1)(b), V(1)(d), V(2)(b).