There is growing interest among scholars and policy makers to develop sustainable entrepreneurial competences in pre-emerging, frontier markets characterized by limited access to advanced capital, high protectionism, and weak formal institutional environments. To become internationally competitive, these markets need to radically rethink their long-standing, embedded practices, which have often been linked to socioeconomic inequality. Our study, grounded in corporate entrepreneurship, is an exploratory analysis of why and how well-established firms, operating in the financial service industry, created more equity-based businesses practices to enter the new industry of mobile banking. The firms in our study needed a combination of both economic incentives and social pressures to do so but, in the process, developed new entrepreneurial competencies. Successful firms were those that significantly altered their embedded practices and engaged in fostering new informal relationships with previously overlooked stakeholders, particularly customers from indigenous backgrounds. Our multi-case, inductive research design offers theoretical and practical insights regarding how incorporating internal and external corporate entrepreneurial factors in an underserved market setting, such as the frontier market of Guatemala, not only fosters socioeconomic equality but also creates international attractiveness and competitiveness.