The comparability analysis plays an important role in the Court of Justice of the European Union (CJEU)’s case law on the fundamental freedoms: if the situations examined are not objectively comparable, a violation of the fundamental freedoms is not possible. However, the CJEU does not follow a clear line in its decisions with regard to the comparability analysis, which makes it difficult to understand the decision-making process. Legal uncertainty is the result. In its last decision, Aures, in which the Court had to deal with a loss utilization rule, it exceptionally denied the comparability of the situations. Due to the increasing significance of losses in international tax law, the authors analyse the different methods of comparability analysis in cross-border loss utilization used by the CJEU and highlight the associated problematic areas.