Blacklisting is a widely used yet controversial instrument aimed at encouraging tax havens to alter their domestic policies, particularly in the wake of the Global Financial Crisis. International organizations such as the OECD and the EU have published tax haven blacklists, but these have been criticized for their limited effectiveness as policy tools. This paper examines the political rationale behind the EU’s blacklist, by focusing on the potential role of public opinion as a driver of policy change. Specifically, we ask whether the threat of blacklisting – through naming-and-shaming or economic sanctions – can shape public attitudes toward tax reform in low-tax jurisdictions. To do this, we conduct an original survey experiment in Switzerland, and show that both a ‘naming-and-shaming’ and an ‘economic threat’ treatment significantly increase public support for tax reform, though estimated effect sizes are modest. These results provide insight into the potential of international instruments like blacklists to mobilize public opinion in support of policy change.