International Organisations Act 2005 – Summary
Privileges, immunities and facilities of international organisations
(322 words)
This Act makes provisions concerning various international entities conferring privileges, immunities and legal capacity on them (supplementing the International Organisations Act 1968).
Commonwealth Secretariat (ss. 1-3): The Act does not have retrospective effect on any contracts entered into before the commencement of this Act. “[T]he President and members of the Commonwealth Secretariat Arbitral Tribunal” are added for purposes of immunities and privileges – i.e. the Secretariat is given full immunity like other international organisations. Should the Commonwealth Secretariat Arbitral Tribunal be replaced, the Secretary of State may amend the Commonwealth Secretariat Act 1966 (with approval by each House of Parliament) with a view to conferring the same immunities and privileges to the successor. In addition, Commonwealth Secretariat officers and servants should hereinafter be exempted from income tax for their salaries and emoluments received in their capacity as officials for that organisation (the change does not apply to those who are no longer officers or servants of the Secretariat).
Organisation for Security and Co-operation in Europe (OSCE) (s. 4): The OSCE is to be treated as an international organisation, regardless of claims that it lacks international legal personality that is separate from its participating states.
EU Treaty Bodies (s. 5): The Crown may confer on bodies created by the Maastricht Treaty the legal capacities of a body corporate, as well as privileges and immunities on such bodies (including persons such as officers, staff or other connected individuals specified in an Order in Council).
International Criminal Court (ICC) (s. 6): The section adds family, household members and persons attending Assembly meetings to the list of individuals covered by the supplementary provisions of the International Criminal Court Act 2001 concerning privileges and immunities.
European Court of Human Rights (ECHR) (s. 7): The section extends privileges relating to international judicial proceedings to members of an ECHR judge’s family.
International Tribunal for the Law of the Sea (ITLOS) (s. 8): The section recognises ITLOS as an international organisation.
Updated 19 March 2026
This summary of the International Organisations Act 2005 is broadly accurate as a description of the Act’s provisions at the time of enactment. The Act remains in force and the sections described continue to reflect its substantive content.
One area requiring reader attention concerns section 5 on EU Treaty Bodies. Following the United Kingdom’s withdrawal from the European Union and the entry into force of the European Union (Withdrawal) Act 2018, provisions relating to bodies created by the Maastricht Treaty and other EU instruments must now be read in the context of the broader post-Brexit legal framework. Retained EU law has been substantially affected by the Retained EU Law (Revocation and Reform) Act 2023, and readers should be aware that the practical relevance of s. 5 in a domestic context has changed significantly, even if the provision itself has not been expressly repealed. Care should be taken not to assume that the Crown’s powers under s. 5 operate in the same way as before exit day.
The remainder of the Act — covering the Commonwealth Secretariat, OSCE, ICC, ECHR, and ITLOS — does not appear to have been materially amended and remains current. Readers should nonetheless consult legislation.gov.uk for the latest version of the Act and any Orders in Council made under it.
