In 2019, the EU Member States started applying the Matrimonial Property Regulation, which concerns the property regimes of international marriages. This regulation is aimed at helping couples manage their property and divide it in case of divorce or the death of one spouse. One of the main features of this regulation is its openness to the parties’ choice. The parties are enabled – in cases foreseen in the regulation – to grant jurisdiction to the court of a Member State of their choice, as well as to choose the law applicable to their matrimonial property regime. Since this regulation is new and the track record of its application is rather short, the limits of party autonomy allowed under the regulation and its advantages still involve a high degree of uncertainty. This article provides an in-depth analysis of party autonomy as provided for in the Matrimonial Property Regulation. In addition, it scrutinises the issue of party autonomy in the Succession Regulation, which often directly interacts with the Matrimonial Property Regulation.