This research, applied to the service context, aims to shed light on the relationships between the different actors in the commercial relationship through the construct of commitment. Our literature review focuses on the concepts of organizational commitment (OC) and brand commitment (BC) as well as on concepts and mechanisms related to the employee-customer relationship. Empirically, we chose to study the relationship between employee commitment and customer commitment in the banking sector. To do so, we use structural modeling to study the possible influence of employee commitment on customer commitment. The results show that, within the branches of the studied bank, the influence of overall employee engagement on overall customer engagement is always verified. On the other hand, the influence of EO components on ME components is not always verified. These results add to the knowledge on the customer-firm relationship in the case of the French market. Nevertheless, this work presents certain limitations inherent to the chosen methodology and the context of the study.