ABSTRACT Purpose Given the dangers of climate change, a nascent body of research emphasises the significance of business-to-business (B2B) firms’ views on implementing climate change policies (CCP) and its links to corporate reputation. Firms are implementing CCP, but face a range of challenges from various stakeholders. We examine the importance of buyers’ attitudes toward CCP implementation as a driver of corporate reputation using legitimacy theory as a theoretical lens. Design/methodology/approach A serial mediation model considering the engagement and commitment of suppliers was explored to assess the proposed relationship. In a two-stage quantitative research design executed in India, data was collected from 109 buyers from B2B firms to refine the measurement scales and then from 503 buyers from B2B firms to test the research model. Findings Using SPSS macro-PROCESS (Model-6), we found both the engagement and commitment of suppliers to be independent mediators of the relationship between the buyers’ attitude toward CCP implementation and their firms’ corporate reputation. Moreover, the engagement and commitment of suppliers toward CCP implementation partially mediated this relationship serially. Policy implications are presented that can be useful in developing corporate strategies to reduce environmental risks and improve the company’s reputation, bringing more business in the long run. Originality/value The study is significant as we conducted it when the United Nations called on all organizations to participate in the Race to Zero, intending to build sustainable businesses. This study contributes original value by demonstrating how buyer attitudes toward CCP implementation, mediated by supplier engagement and commitment, significantly influence corporate reputation, thereby offering actionable insights for developing sustainability strategies in B2B contexts.