FinTech is an emerging technology comprises of two words i.e. financial and technology. FinTech is proving to be a disruptive technology and is meant to help users in managing their day-to-day financial activities. The FinTech industry is growing up enormously in Pakistan for the last few years, due to the continuous development in information technology; user expectations are continuously increasing in financial services owing to transparency, convenience, privacy and security, moreover, it has simple and effective interface. However, usability issues of FinTech mobile applications across various age groups are still unclear. Usability is the key feature in mobile apps because the term usability is associated with both performance and satisfaction, various questionnaires were conducted among various age groups in this study, and results were analyzed separately by gender. In this study, we found out and elaborate the usability of FinTech mobile apps among various age groups through a quantitative survey and progressively centered analysis around features affecting the elderly people on adopting FinTech mobile apps in Pakistan. Therefore, a quantitative analysis have been applied on the collected data to figure out the issues of FinTech in detail, which currently has impact on the quality of FinTech mobile apps directly and indirectly. It also provides comprehensive statistical analysis by analyzing and applying on respondents' profile, frequencies, T-test, reliability test, nonparametric test and descriptive studies through SPSS. Therefore, the interface design must be easy to use for everyone, especially for the elderly. Using the finance related Information apps on cell phones in a superior manner will improve the user's satisfaction. It proves that, the interface design guarantees the success of any mobile app.