Digital transformation in the public sector demands helpdesk services that not only meet user needs but also implement effective, measurable, and sustainable IT governance. However, current evaluations of government digital services are often fragmented, focusing separately on either user satisfaction or internal governance, which fails to provide a comprehensive view of service quality. This study evaluates the effectiveness of the BKKBN DIY Helpdesk Service by integrating the COBIT 2019 framework, Customer Satisfaction Index (CSI), and Importance-Performance Analysis (IPA). Employing a mixed-methods approach with a sequential explanatory design, the study utilized the COBIT 2019 Design Toolkit to identify thirteen priority Governance and Management Objectives (GMOs). Data were gathered through documentation reviews, observations, interviews with management, and user surveys. The analysis involved a COBIT 2019 capability assessment, CSI framework calculations, and service attribute mapping using the IPA framework. The findings reveal a user satisfaction level of 79.25%. However, the capability assessment indicates that several priority objectives fall short of the organization’s targets, highlighting governance gaps that require improvement. Furthermore, the IPA framework successfully identified critical service attributes that demand immediate attention to optimize overall service quality. By integrating a Design Factor-based COBIT 2019 capability assessment with CSI and IPA, this study contributes a holistic evaluation framework that bridges IT governance and user satisfaction, offering a practical, measurable roadmap for sustainable helpdesk service enhancement.Â