Starting with its judgment in the Marks & Spencer case on the cross-border loss utilization of non-resident subsidiaries and in the Lidl Belgium case on permanent establishment losses, the ECJ has successively specified the concept of final losses in its case law. This article aims to compile, analyze, and critically assess the ECJ’s previous statements on the finality of foreign losses. The aim is to develop a list of criteria for assessing the finality of foreign losses based on the case law of the ECJ and the legal opinions in the literature. In addition, it will be shown which issues have not yet been conclusively clarified and which tendencies can generally be derived from the case law of the ECJ.