Ad Hoc Arbitration

Ad hoc arbitration is a method of dispute settlement in which the disputing parties—rather than a permanent arbitral institution—organise the proceedings themselves. The parties select the arbitrators, agree on the seat, language, and procedural timetable, and bear direct responsibility for administering the case. This contrasts with institutional arbitration, where bodies such as the ICC International Court of Arbitration, the LCIA, or the SCC supervise the process and apply their own rules.

In international practice, ad hoc proceedings most often rely on the UNCITRAL Arbitration Rules, first adopted by the UN General Assembly in 1976 and revised in 2010 and 2013. These rules supply a procedural framework while leaving the parties broad autonomy. The Permanent Court of Arbitration (PCA) in The Hague frequently acts as registry or appointing authority in ad hoc cases, even though the proceedings remain formally non-institutional.

Ad hoc arbitration is common in:

• Inter-state disputes, including boundary and maritime delimitation cases.
• Investor-state disputes brought under bilateral investment treaties that offer UNCITRAL Rules as an alternative to ICSID.
• Commercial contracts between sophisticated parties seeking flexibility and lower administrative fees.

Notable examples include the Iron Rhine arbitration between Belgium and the Netherlands (award 2005) and the Arctic Sunrise case between the Netherlands and the Russian Federation under Annex VII of UNCLOS (award 2015), both administered by the PCA on an ad hoc basis.

The principal advantages are flexibility, confidentiality, and cost control. The principal risks are procedural deadlock if one party refuses to cooperate, and reliance on the lex arbitri of the seat for default rules and judicial support. To mitigate these risks, well-drafted arbitration clauses typically designate an appointing authority (often the PCA Secretary-General) to resolve impasses over arbitrator selection.