Abstract The international community has developed hundreds of intergovernmental agreements to address global sustainability issues, and market and civil society actors have supported this effort by taking numerous initiatives themselves. As a consequence, different public and private institutions interact and influence each other, creating a complex governance system working towards sustainable development, and the call for synergies among the various initiatives is increasingly being heard. An example is the issue of reducing emissions from deforestation and forest degradation, REDD+, in which different international institutions are active, including the World Bank’s Forest Carbon Partnership Facility (FCPF) and Forest Investment Program (FIP), and the United Nations UN-REDD Programme. This chapter introduces a ‘practice turn’ to the scientific debates on institutional interactions and their management, with the aim of elucidating how the institutional interactions on REDD+ are being managed in practice, and why they are being managed the way they are. The analysis shows that interaction management practices are especially influenced by the partner countries and NGOs involved in REDD+ institutions, and that different ‘logics of practice’ have developed over time, including strategic interaction management, which we have labelled ‘meta interaction management’. Interaction management on more contentious issues, such as stakeholder engagement, is shown to be rather difficult, and thus less far-reaching.