Traceability of ingredients in food supply chains has become paramount in a world in which markets become global, heterogeneous, and complex and in which consumers expect a high level of quality. The food supply chain consists of many organizations having different interests and are often reluctant to share traceability information with each other. Blockchain has been advocated for improving traceability by providing trust. Yet, practice proved to be more stubborn. The goal of this paper is to identify boundary conditions for sharing assurance information to improve traceability. Four cases in the food supply chain have been investigated using a template analysis of 16 interviews. Eighteen boundary conditions categorized in business, regulation, quality and traceability categories have been identified. Some boundary conditions were found in all supply chains, whereas others were found to be supply chain specific. Standardization of traceability processes and interfaces, having a joint platform and independent governance were found to be key boundary conditions before blockchain can be used. Our findings imply that supply chain systems have first to be modified and organizational measures need to be taken to fulfill the boundary conditions, before blockchain can be used successfully.