The discourse on State immunity has traditionally focused on its application in judicial proceedings. However, in recent years scholars have begun to address whether the law on State immunity also protects foreign States against measures taken against their property by the territorial State's executive and/or legislative organs. This question has been raised following unilateral sanctions regimes freezing property of foreign States. It has gained renewed attention in the context of the ‘immobilization’ of around €300 billion of the Central Bank of Russia's assets as a reaction to the invasion of Ukraine by the Russian Federation. In addition, there are recent suggestions to subject these sovereign assets to further steps, including confiscation, the generation of investment returns or taxing windfall profits accruing to the entities holding the assets. This article revisits the various conceptions of the law on State immunity to address the question of whether a principle of State immunity against non-judicial measures of constraint exists. Based on a review of existing State practice and opinio juris, it argues that customary international law does provide for State immunity in this context. However, the article further contends that the content of the norm should be construed differently than in relation to judicial proceedings, recognizing the weight of public policy concerns of the territorial State.