The United Kingdom (UK) signed the UN Convention on Jurisdictional Immunities of States and their property (Convention) less than a year after it was adopted by the UN General Assembly.1 The signature came only a few months after an open, but not well publicized, consultation with academics and society,2 and several months before a crucial appeal, in which the Secretary of State for Constitutional Affairs is a party, is heard by the House of Lords of a decision permitting a civil suit to proceed against foreign government officials for torture committed abroad.3 Despite the signature, the UK has not yet announced whether it will ratify the Convention and, if so, whether it intends to do so with an understanding, declaration or reservation.4 As discussed below, it appears that the Convention might preclude victims of genocide, crimes against humanity, war crimes, torture and other crimes under international law, as well as other human rights violations, committed abroad from recovering civil reparations in UK courts against states or their current of former officials or agents. In the light of the numerous ambiguities in the Convention and the risk that it will be interpreted by national courts as barring such reparations in those courts, the UK should not ratify it until a protocol is adopted expressly guaranteeing victims and their families the right to recover reparations in such cases.