In India's digital payment ecosystem, the Buy Now Pay Later (BNPL) category has become one of the fastest-growing financial innovations, particularly among young and tech-savvy customers. With an emphasis on knowledge levels, usage patterns, trust, convenience, risk perception, and financial behavior, this study investigates the key variables impacting consumer choice for BNPL FinTech services in Thoothukudi.  Using a standardized questionnaire, 140 respondents provided primary data for the study, which was then analyzed using descriptive statistics and ANOVA tests.  The results show that the majority of BNPL users are from lower and middle-class backgrounds and that their primary motivations for using BNPL are convenience, speedy approval, and flexible payment alternatives.  The results also demonstrate that, except from views on equitable collection methods, age has little effect on concerns about debt increase and financial stress, while educational attainment has a significant influence.  According to the survey, while BNPL services improve short-term affordability and shopping ease, consumers need to be more conscious of hidden fees, payback requirements, credit score consequences, and responsible usage.  In order to guarantee the safe adoption of BNPL services in developing digital marketplaces like Thoothukudi, the study emphasizes the necessity of more robust consumer education and open policies