The Republic of Mozambique (acting through its Attorney General) v Credit Suisse International & Ors

Service of proceedings abroad must comply with the law of the country of service. Where that law requires service through its judicial authorities, direct delivery at a presidential security checkpoint is insufficient, and the party asserting valid service bears the burden of proof.

Under section 20 of the State Immunity Act 1978, the reference to the Diplomatic Privileges Act 1964 and necessary modifications does not permit removal of the territorial restriction in Article 31(1)(c) of the Vienna Convention. A serving foreign head of state therefore retains personal immunity from English civil jurisdiction for private commercial activity conducted outside the United Kingdom.

The Republic of Mozambique brought substantial civil and commercial proceedings against various defendants. Certain defendants joined President Nyusi as a fourth party, alleging contribution as a joint tortfeasor, unlawful means conspiracy and deceit under Mozambican or English law.

Permission to serve proceedings out of the jurisdiction had been granted in 2021. The defendants claimed that service had occurred directly in Mozambique on 19 October 2021, while President Nyusi contended that he was served only through the Mozambique Court on 14 April 2023. He then challenged jurisdiction on the basis of his status as a serving head of state.

The issues were whether service had occurred in 2021 and whether section 20 of the State Immunity Act 1978 excluded personal immunity for alleged private commercial activity undertaken outside the United Kingdom.

1. Service. The documents left with police and security officials at the Presidential Palace and Office of the President on 19 October 2021 had not been served. Mozambique was a Commonwealth State not party to the Hague Convention. The applicable rules required service through the Mozambique judicial authorities, or service by a method permitted by Mozambican law. The Privinvest Defendants had produced no evidence that the direct method used was permitted by, and not contrary to, Mozambican law. Service was therefore effected on 14 April 2023 through the Mozambique Court.
2. Statutory framework. Section 20(1) of the State Immunity Act 1978 applies the Diplomatic Privileges Act 1964, subject to necessary modifications, to a foreign head of state. The threshold is necessity, not desirability or convenience. Article 31(1)(c) of the Vienna Convention excludes immunity for professional or commercial activity exercised in the receiving State outside official functions. The words referring to the receiving State could not be removed merely because a wider exception might appear logical or desirable for heads of state.
3. Construction and purpose. The amendment of section 20 to apply irrespective of the head of state’s presence in the United Kingdom addressed the duration and territorial reach of personal immunity. It did not require reducing the substantive immunity enjoyed during a visit by removing the territorial limit in Article 31(1)(c). The distinct statutory foundations of sections 3 and 20 of the State Immunity Act 1978 prevented the commercial exception for state immunity from being transferred into section 20 by analogy.
4. Conclusion. Section 20 recognised, and did not exclude, President Nyusi’s immunity from the jurisdiction of the Court in these proceedings while he remained Head of State. His immunity challenge succeeded. The Court did not need to determine the remaining arguments; the separate allegation of inadequate disclosure had no merit.

First-instance decision. The judgment discusses, but does not determine, the unresolved issue considered in Apex Global Management Ltd v Fi Call Ltd and Others.