Customer loyalty is an essential concern for the telecommunication sector in modern customer processes. Therefore, customer retention processes and knowledge for customer are widely used in the competitive environment to achieve customer loyalty. The purpose of this paper is to suggest a model that defines how the combination between customer retention processes and knowledge for customer would achieve the customer loyalty. This paper adapts the quantitative research approach by using the survey strategy, which is conducted by a questionnaire collected from 193 people working in the management position of Jordanian telecommunication organisations. The researcher uses the Smart partial least square (PLS) as an analysis technique to test all hypotheses. The findings suggest that there is a positive effect of adapting the customer retention processes in improving the customer loyalty mediating by the knowledge for customer.