Annulment of ICSID and non-ICSID investor-State arbitration awards: emerging trends

A recent empirical study of 170 annulment proceedings in domestic courts, in conjunction with a previous analysis of ICSID annulment proceedings, has provided valuable insights into how investor-State arbitration awards fare under the scrutiny of domestic courts.

An ICSID award can be annulled by an ad hoc committee under one of five grounds laid down in Article 52(1) of the ICSID Convention. Such a remedy is considered exceptional. Although it is States who more frequently apply for annulment, it is, in fact, investors who succeed most often.

As to annulment proceedings in the domestic courts, the study identified England & Wales, Sweden and France as the jurisdictions with the highest success rates for the annulment of awards. As regards Sweden in particular, the jurisdiction stands out due to intra-EU treaty challenges following the judgments of the Court of Justice of the EU in the Achmea and Komstroy cases.

Such findings reinforce the importance of procedural integrity and due process in the enforcement and sustainability of arbitral awards.

Gherson advises clients on the recognition, enforcement and annulment of investor-State arbitration awards, often in cases intersecting with sanctions and public international law.

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Source: Empirical study by the British Institute of International and Comparative Law (BIICL) and Baker Botts LLP on annulment of investor-State arbitration awards in domestic courts (2025).