The purpose of the final project is to determine which factor between personal factor and psychological factor that affects customer’s decision to use postpaid electricity services and to find out which aspect should be improved. This final project was arranged based on questionnaires and study literature. The variable of this final project are personal factor, psychological factor and customer’s decision to use postpaid electricity services. The sampling technique that used in this final project was probability sampling methods. The Population of this final project were customer of PT PLN (Persero) Rayon Semarang Timur. The Samples of this final project were 100 respondents. The results showed that personal factor have more impact to customer’s decision to use postpaid electricity services. This can be seen by the result from the calculation of the regression coefficient. Personal factor had regression coefficient value amount of 0,515, while psychological factor had only 0,338. The conclusion is personal factor had bigger impact for customers to use postpaid electricity services.