Background: The importance of transitioning to a more sustainable and circular production and consumption model is growing, with the looming threat of climate change. The supply chains (SC) are at the foreground of this change, with the linear model as a polluter of magnitude. Transitioning to a circular supplychain (CSC) is a massive undertaking, and barriers may arise between SC partners embracing this significant change. However, the literature is vague on which barriers are significant within buyer-supplier collaboration and how to address and overcome the barriers that may stand in the way of implementing CSCs.

Purpose: The purpose of this thesis to explore to investigate how to support circularity implementation in SCs through dyadic buyer-supplier collaboration. By exploring the collaboration barriers presented in academic literature, this study aims to contribute to a deeper understanding of which barriers can arise during collaboration when implementing circularity in the SC, while linking relevant actions to address these barriers. Thereby providing new insights to practitioners who wish to implement circularity in their SC.

Method: A multiple case study method with four interior textile companies were studied with the help of collaboration barriers when implementing CE in the SC from existing literature. By using a qualitative research approach, data was collected through ten interviews.

Conclusion: Five major barriers occur in buyer-supplier collaboration when implementing circularity in the SC within the case companies. Including (1) lack of shared vision, (2) lack of commitment, (3) lack of capable suppliers, (4) lack of transparency, (5) and lack of power balance between buyer-supplier. To address the five barriers, five action groups emerged from the case companies, (1) communication, (2) supplier engagement, (3) education, (4) addressing cultural differences, and lastly (5) long-term commitment. These barriers and actions are matched to each other in a framework and summarizes the finding of this study.