This study aims to assess the possibility of failure or success of the national complaint handling system in Indonesia, LAPOR!, using the design–reality gap model. It is crucial because the implementation of LAPOR! has encountered some obstacles, allowing for failure and impacting the system’s sustainability. Data were collected through interviews with LAPOR! stakeholders. Gap assessment of the system was conducted by experts. The study showed that the design and reality gaps of LAPOR! are still large. The gaps found in LAPOR! must be reduced so that the risk of system failure can be mitigated early on. Administrators of LAPOR! must pay attention to social and technical elements in the operation and development of this system in the future. Copyright © 2023 Inderscience Enterprises Ltd.