AbstractThis study examines the changing use of controls to manage an ongoing inter‐organisational collaborative relationship. We do this by studying the development of an open innovation relationship using a case study informed by concepts from neo‐old institutional economics and Simons’ levers of control. Data was collected via semi‐structured interviews and an analysis of documents. Our findings suggest that initially, governance structures and formal safeguards were applied diagnostically, which resulted in low levels of trust. Over time, the development of a collaborative relationship through investments in relational specificity has resulted in a more interactive style of control, which has increased trust.