The article aims to identify the main factors affecting customers' decision to use mobile banking service in Vietnam, a case study in Thanh Hoa province. Based on theoretical frameworks of the Technology Acceptance Model (TAM) and the Unified Theory of Acceptance and Use of Technology (UTAUT), the study has been conducted with 370 questionnaires to consumers who have not yet used and are currently using mobile banking in Thanh Hoa province. The research results indicates that several factors have been evaluated to be more important than others, of which, the social influence is the strongest, the second is the compatibility and some others factors such as perceived ease of use, perceived trust, etc., all affecting the intention to use mobile banking in Thanh Hoa. Based on these important results, the article propose a number of recommendations: (i) Exploiting the advantages of social influence on the increase of intention to use; (ii) Increasing compatibility and minimizing costs for customers when they use Mobile Banking; (iii) Developing a strategy to increase the users’ perceived ease of using banking services; (iv) Issuing a policy on increasing the security of Mobile Banking system to meet customers’ needs; and (v) Developing an individual customer management system to improve service quality.