This study examines the development of the Association of Southeast Asian Nations (ASEAN)’s Self-Certification of Origin mechanism through two key phases. From 1993 to 2015, ASEAN strove to establish a common market and deepen economic integration. During this period, it introduced various pilot projects to enhance trade, streamline certification procedures, and experiment with trade facilitation initiatives. Following the official establishment of the ASEAN Economic Community in 2015, the focus shifted towards harmonizing trade procedures, enhancing regional coordination, and standardizing customs processes. These efforts culminated in the launch of the ASEANwide Self-Certification (AWSC) in 2020. In Vietnam, however, the implementation of AWSC has faced significant challenges. Despite these obstacles, the country has taken proactive steps to integrate AWSC into its trade system by issuing domestic regulations and guidance from regulatory authorities. This study explores the specific difficulties Vietnam faces in implementing AWSC and proposes recommendations to enhance its effectiveness.