This paper analyses the effect of brand positioning on customer loyalty. Based on data of a survey of clients of the energy utility Iberdrola, the study measures the loyalty effect of the company's perceived positioning For this purpose, a positioning model of the company and its main competitors is developed, as well as a set of loyalty indicators of the company's clients. The regression analysis show a significant effect of the dimensions of the company's positioning on the set of loyalty indicators. The results of the study emphasize the importance of brand positioning in the context of customer loyalty management.