This study provides new insights into factors that enable effective triangular co-operation. These include sound national ecosystems to support triangular partnerships through high-level political will, guiding documents, institutional structures, partnerships, resources and management procedures. Furthermore, against the background of the 2030 Agenda and the outcomes of BAPA+40, a shift of thinking from ‘donor-recipient’ relations to ‘partnerships’ needs to run through political discourse, public opinion, strategies and systems of all partners in triangular co-operation. Moreover, for the first time, the issue of ‘transaction costs’ in triangular co-operation is discussed systematically. Based on the research, interviews, and meetings that were conducted for this study, broad agreement emerged that these are investments in the partnership, and should not be regarded as costs. Finally, five options to engage effectively in triangular co-operation are offered. The decision for one of these five approaches, depends on the specific context of the partners that wish to set up new triangular co-operation initiatives. There is no one-size-fits-all approach, thus this study aims to contribute ideas and policy implications based on existing experiences and evidence.