This project focused on the development and implementation of an online school fees management system in Secondary School in Liberia, addressing inefficiencies and challenges associated with manual fees collection processes. Utilizing technologies such as UML for system analysis, Xampp for database creation, and PHP—a widely-used server-side scripting language—integrated within HTML, the system aimed to create dynamic web pages that interact with databases, process form data, manage sessions, and handle tasks like sending and receiving cookies. PHP, which runs on the server, generates HTML that is sent to the client's browser, making it suitable for building interactive, data-driven websites. It easily interfaces with many different databases, such as PostgreSQL, MySQL, and SQLite. The front-end development was achieved using HTML, CSS, bootstrap and JavaScript (JS), alongside PHP for back-end functionalities. The system was designed to minimize the use of paper, reduce administrative costs, and improve the quality of service to students and parents, while enhancing data management and financial transparency in fee collection and tracking. The implementation led to significant improvements, including a substantial reduction in fee processing times, leading to enhanced efficiency and streamlined school operations. The transparency of the fee payment review and approval process increased, promoting fairness and accountability. Data accuracy, accessibility, and compliance with financial regulations were significantly enhanced through the integration of relevant databases and frameworks. In conclusion, the adoption of the online school fees management system proved advantageous for educational institutions in Liberia by reducing administrative burdens, ensuring compliance with financial regulations, and improving communication between schools, parents or guardians. The system notably enhanced efficiency, transparency, and financial management in fee collection processes, enabling more effective school administration. Recommendations include regular system updates and enhancements to meet the evolving needs of educational institutions and technological advancements. Comprehensive testing was conducted to ensure the system meets user needs and performs as intended.