A web-based application for managing office supplies (ATK) inventory at Bank Mandiri, Commercial Banking 5 & 6, is designed to improve efficiency in real-time recording of incoming and outgoing items. Barcode technology is applied to minimize manual input errors, and automatic notifications are integrated to provide alerts when stock levels are low. The development method uses Rapid Application Development (RAD) due to its flexibility and fast iterations. This system supports decision-making based on more accurate data. Previous research has shown that the RAD method and similar technologies are effective in enhancing operational efficiency.