Digitalization in the payment system has been promoted by the Indonesian government since the government is targeting to become the largest digital economy in Southeast Asia. However, not all companies can adopt digital payments quickly. Small and Medium Enterprises (SMEs) have many obstacles to adopt innovative technologies, mainly due to a lack of knowledge and resources. On the other hand, many consumers are getting used to digital payments and demanding SMEs to facilitate their transaction processes with digital payment systems. Therefore, the primary purpose of this study is to analyze factors affecting the digital payment system adoption in SMEs, particularly small and medium-sized restaurants. It used an extended Technology Acceptance Model (TAM) as a theoretical framework. Thus, 120 data were gathered using self-administered questionnaires from owners or managers of small and medium-sized restaurants in Bogor, Indonesia. Structural Equation Modeling with Partial Least Square (SEM-PLS) was employed to assess the hypotheses that were developed. The findings suggested that the intention to use digital payment was determined by the perceived ease of usage, perceived usefulness, attitude towards digital payment, and trust. This research approved that the applicability of TAM with the inclusion of additional variables in the model and the adoption of the digital payment system in small and medium-sized restaurants in developing countries like Indonesia. It offers valuable information for policymakers and financial institutions such as banks in understanding the critical variables influencing large scale implementation of the digital payment system in Indonesia.