The objective of this research is to develop a payment notification system via the LINE application, aiming to enhance the efficiency of revenue tracking and payment status verification with accuracy and real-time capabilities. The system was developed as a web application, utilizing the Go language for server-side processing, the Svelte framework for the user interface development, and DBeaver for database management. The system operation is divided into two main components 1) the User side, which supports payment status notifications and order summary visualization, and 2) the Administrator side, designed for data management and payment receipt verification. The system performance was evaluated through functional testing, response time measurement, and data integrity verification. The results indicated that the system is capable of delivering real-time payment notifications with an average response time of 2.35 seconds. The data accuracy of the notifications was found to be 100 percent. Furthermore, the system correctly processed and visualized daily and monthly sales comparison reports according to the specified conditions. These findings demonstrate that the developed system reduces time and errors in financial verification compared to traditional methods and effectively supports entrepreneurs in sales data analysis.