The excitement about concluding the Paris Agreement is giving way to the sobering realization that a lot more needs to be done to attain its climate policy objective. More and more Member States in the European Union embrace carbon taxes but the national measures differ strongly. In an integrated European market this challenges the level playing field of competing industries and the transboundary nature of regulating a global pollutant and calls for a solution on EU level (or higher). Past attempts to regulate carbon emissions at EU level by fiscal measures have, however, been markedly unsuccessful. This paper therefore examines introduction issues and barriers of a CO2 tax at EU level and offers policy suggestions to move forward.