This study aims to analyze business processes related to revenue and cash collection of PDAM Lematang Enim and aims to provide an internal control design of the business process. The method in this research is descriptive analysis in the form of case study. Data have been obtained through document analysis, observation, and in-depth interviews with informants such as general director, technical director, chief financial officer, and finance staff. The results show that there are some weaknesses of PDAM Lematang Enim management in optimizing the cash collection process from customers. These weaknesses have an impact on increasing value of receivables and the value of allowance of bad debt. The company has not implemented formal and structured internal controls, so business processes are only run and controlled by custom.