New digital technologies are a driving force behind many pivotal changes in our modern world. For example, the carsharing business model has improved drastically through the adoption of technologies for online booking, instant access, vehicle monitoring, and automated billing. However, the challenge of vehicle supply and demand management hinders carsharing from reaching its full potential and mainstream application. The current norm of relocating vehicles via employees is expensive and unsustainable, counteracting the environmental benefits of carsharing. To engage this problem, a new concept called user-based relocation has emerged in recent years. For user-based relocation, customers are requested to return rented vehicles at undersupplied locations. However, research and practice lack knowledge on how to implement user-based relocation in a real-world carsharing system. This study employs an iterative research approach, including the implementation of user-based relocation in a real-world carsharing system. During the development and evaluation process, novel requirements and challenges for user-based relocation were discovered, providing valuable knowledge for its implementation and future research.