Purpose – The complexity and resulting opacity of TC supply chains, and the fragmentation of approaches to traceability to address these issues, revealed the necessity of collaboration for traceability in TC supply chains. Although the challenges have been explored in literature and practice, it has been left unstudied how collaboration can overcome these challenges. Further, current literature is limited to focus on buyer-supplier relationships rather than the inclusion of external supply chain (SC) actors despite their important role in the implementation of SC traceability. Acknowledging the need for broadening the perspective from dyad to network level, the purpose of this study is to examine collaborative relationships for implementing traceability in the extended TC supply chain network, and thus identify collaborative challenges and possible improvement opportunities. Design/methodology/approach – This research was based on a multiple case study method of three relationship types considering primary data from semi-structured interviews and documentary secondary data related to the studied organizations. While embracing an abductive approach by extending the AARI framework by Welch and Wilkinson (2002) to the context of traceability in TC supply chains, the data analysis followed the Grounded Theory methodology of open, axial and selective coding. The findings of the dyadic relationships were discussed by their substance layers and cross-case comparison. Findings – Through the extended model, the findings shed light on the role of collaborative relationships in the implementation of SC traceability and their interconnectedness on the network level. Based on developing preconditions for dyadic relationships, deductions for the network level could be made. Further, the essential role of external SC actors for the implementation of traceability in the TC supply chain network indicated the necessity of considering collaboration with the extended network. Consequently, possible improvement opportunities for implementing traceability through better collaborative relationships in the extended TC supply chain network could be detected. Originality/Value – This study adds to the theory of network relationships and literature of traceability in TC supply chains by focusing on collaboration in the extended network. It creates new insights by including the ideological dimension. By considering possible chain dependencies of relationships and the interrelation of schema couplings with resource ties and activity links, it can offer practitioners a better understanding of the network behavior and possible challenges in relationships. The proposed set of preconditions can provide inspiration and a change in perspective for successfully collaborating to implement traceability in TC supply chain networks.