This policy briefing discusses decarbonization policies of “hard-to-abate” sectors, emphasizing the implications of these sectors’ complexity. Specifically, we discuss two sources of complexity: (a) heterogeneity in the form of variation across and within technologies and user segments and (b) interdependencies between technologies (within and between their value chains) and between user segments and adopter groups. Based on research on coastal shipping in Norway, a global frontrunner in decarbonization of this sector, we suggest three guiding principles for developing policy mixes for decarbonizing hard-to-abate sectors: (1) employ technology-specific policies but aim at broad sectoral or general policies when suitable, (2) consider value chain interdependency and user segment heterogeneity when prioritizing technologies and user segments, and (3) translate (rather than transfer) successful policies to other settings (e.g. user segments).