Single-use plastics reduction is the primary mission of SDG promotion in Thailand. This study discusses the implementation and challenges of plastics reduction campaigns through interviews and field investigations focusing on stakeholder participation and perceptions of policy approaches in Bangkok. Convenience and economic factors are the major challenges for reduction practices in addition to insufficient financial support and the weak participation of stakeholders, all of which lead to the avoidance of penalties, reliance on voluntary collaborations, and market-led measures. The implementation of a ban without preparation guidelines for alternatives, practices, and an unequal regulatory scope has created tensions for consumers and businesses. Suasive instruments drawing on consumer merit, emotion, and ethics, in addition to incentives that lead to the perception of benefits related to single-use plastics reduction, could provide a motivation for society and shift current behaviors. Policymakers need to collaborate with academics and NGOs to provide the private sector and consumers with detailed, suitable, and short- and long-term strategies that promote pro-environmental behavior, encourage reuse, and discourage single-use practices—including clear duration times, targets, detailed guidelines, and facilities. The combination of a ban and a penalty, while still offering a fee as an alternative option and maintaining acknowledgment and communication with stakeholders, would result in better consumer feedback.