The introduction of transnational lists is one of the most prominent approaches for a reform of the European electoral law. Various options are being discussed for certain design aspects - for example regarding the size of the transnational seat contingent, the use of preferential votes, etc. Although the proposals have so far failed to achieve the necessary majority in the EP and unanimity in the Council, the political debate around it remains lively. Currently, transnational lists are one of the ideas that have received most endorsements on the digital platform of the Conference on the Future of Europe and play a central role in the draft report on electoral reform that is currently discussed in the European Parliament. European elections suffer from a lack of transnational electoral equality. While there are good reasons for the degressive proportionality of national seat contingents, the resulting distortions in the strength of political groups are a serious stain for the EU's democratic legitimacy. This could be solved through a multi-tier electoral system with proportional compensation. Such a system would keep the current national seat contingents but use transnational lists to make sure that the seat share of each political group corresponds to its EU-wide vote share. This Policy Paper explains with several calculation examples how such an electoral system would work and outlines some challenges for its implementation.