The common service center is unifying the different bill collection centers into one stop payment point to enable the citizens get the services in the integrated and simplified way. This study investigated the effect of service quality of Unified Billing Service on Lehulu Center customers with the level of customer satisfaction at Bahir Dar Town by using SERVPERF dimensions of tangibility, responsiveness, reliability, assurance and empathy. The main objective of this study is to investigate the effect Unified Billing Service quality on customer satisfaction in Bahir Dar Lehulu centers. This study used a survey design by using cross-sectional methods with quantitative research approach to measure both dependent and independent variables at the same point in time and both primary and secondary data were employed. The questionnaire was prepared in the form of Likert-Scale type by constructing into five-point scale. From the total population of 23,136 Lehulu customers, 393 samples were selected by using convenience or judgmental sampling technique of non-probability sampling method and 368 usable questionnaires were returned for the analysis purpose. SPSS version 20 software was used to analyze descriptive and inferential statistical tools of frequency, mean, standard deviation, correlation, and multiple linear regression. The results of this study indicated that the four service quality dimensions (reliability, assurance, responsiveness and empathy) have a positive and strong relationship with customer satisfaction and tangibility has a positive and moderate relationship with customer satisfaction. Furthermore, the five service quality dimensions models significantly explained 55.2% of the variations in customer satisfaction in Lehulu centers of Bahir Dar and they have also a positive and significant effect on customer satisfaction at 99% confidence level. The researcher recommended to give special attention to tangibility. Improve the staffs’ capacity by increasing employees’ ability to handle customers’ complaint and problems in consistency manner is the other recommendation of the researcher.