Extended Producer Responsibility (EPR), which requires producers to take responsibility for the entire life cycle of their products, is a key policy tool for promoting the development of a circular economy and achieving carbon neutrality goals. By examining China's EPR policy practices, this study establishes a quasi-natural experiment based on its mandatory implementation in sectors such as appliances, batteries, automobiles, and paper packaging. Using data from China's listed companies from 2012 to 2022, we employ Propensity Score Matching Difference-in-Differences (PSM-DID) and Synthetic Difference-in-Differences (Synthetic-DID) models to examine its impact on the carbon emissions of regulated enterprises. The findings reveal that EPR reduces the carbon emissions of regulated enterprises by approximately 10.3 % on average, with the carbon reduction effect strengthening over time. Mechanism analysis indicates that EPR influences corporate carbon emissions by promoting green strategies, optimizing green information disclosure mechanisms, enhancing the quantity and quality of green low-carbon technological innovations, and reducing energy consumption during production. Heterogeneity tests indicate that the EPR-driven carbon reduction effect is more pronounced among firms in technology-intensive industries.