Despite access to financial resources, many micro and small-scale entrepreneurs struggle to grow their businesses due to management inefficiencies. This study analyses a globally recognized ILO business training initiative in Indonesia, involving 12 financial service providers in 2018. Using an RCT and panel data from 3,975 clients to study the impacts of the business training we find largely null results across a large range of outcomes. Exploiting variation across financial institutions implementing the program, we show that one financial service provider demonstrated significant improvements in its clients’ behaviours. This uneven outcome suggests that the efficacy of large-scale interventions critically depends on the quality of implementation by individual partners. The overarching conclusions advise restraint in broadly expanding these programs, while simultaneously highlighting the crucial role of partner selection in the successful implementation of these initiatives.