<![CDATA[The growth of the preloved business, which focuses on selling secondhand items in good condition, has seen a rapid upward trend among young people due to its affordability and support for eco-friendly lifestyles. However, BELIPOLO.ID, a store operating in this sector, still encounters operational challenges because its promotional processes utilize social media such as Instagram and WhatsApp, while transaction records and stock updates have not been systematically maintained. These constraints lead to stock monitoring errors, unstructured product data management, and delayed product information for customers. This study aims to build and implement a web-based sales and management information system specifically tailored for the BELIPOLO.ID. The research uses a Research and Development (R&D) approach with the Waterfall development model, covering requirements analysis, design, implementation, testing, and maintenance. The system was developed using the Laravel framework and MySQL and evaluated using Black Box Testing. The system integrates product, category, stock, sales transaction, payment proof, and owner Dashboard management within a single platform. Testing of 10 functional scenarios showed that all scenarios were successfully executed, resulting in a 100% success rate. The implementation also provides automatic stock updates after transactions and presents sales information based on stored transaction data. These results indicate that the system can support centralized and structured management of product, stock, and transaction data.]]>
