The COVID-19 pandemic's outbreak hastened the digital transformation within Indonesian MSMEs. The crisis necessitated an immediate transition to online platforms to sustain business activities, driving many MSMEs to surmount previous reluctance and embrace digital technologies. This research focused on the determinant of intention and use behaviour of fintech payment system among Indonesia MSME's. This study highlights the importance and urgency of understanding the evolving dynamics of digital adoption among Indonesian MSMEs in the post-COVID era, using the UTAUT to shed light on these specific factors. The approach used in this research is quantitative. The sampling technique used was purposive sampling which has selection criteria MSMEs that have engaged with fintech payment systems for at least one year. The sample size calculation utilized the Slovin formula, incorporating a margin of error of 5% got 399 respondents of MSMEs from Surabaya, Indonesia. Data analysis techniques used are the SEM-PLS using SmartPLS-4. The result finding indicate that Performance Expectancy, Effort Expectancy, and Social Influences significantly influence Behavioural Intention. However, Facilitating Conditions do not have a notable impact on either Behavioural Intention or. In addition, Behavioral Intention significantly influence Use Behaviour of fintech payment system in MSMEs. This research enhances theoretical understanding by utilizing the UTAUT model in a novel context, this study not only extends the model's relevance but also definitively ascertains the influence of factors such as performance expectancy, effort expectancy, social influence, and facilitating conditions on the acceptance of FinTech payment solutions. Practically, this study offers government to make MSMEs valuable guidance on formulating digital strategies and surmounting obstacles in FinTech integration. Further exploration into these facets is required in future studies and that policy formulation should better align with the unique necessities of MSMEs during their digital transformation processes.