In the context of fintech and industrial revolution 4.0, the banking system worldwide has significantly developed mobile banking services at a great pace in order to promote economic performance. The aim of this analysis is to estimate factors that impact on the customers' use of mobile-banking services in the typical case in Vietnam nowadays. Using a sample data of 420 questionnaires covering in 2020, the results indicate that brand and social influence have greatly impacted on the customers' use of mobile-banking services. A greater bank’s brand and social influence is positively related to a greater the customers' use of mobile-banking services. In addition, transaction risk has a negative impact on decisions to use mobile-banking services. Vietnam should enhance the risk management in the banking sector in order to maintain sustainable development in the long run.