Abstract: The disclosed technology relates generally to methods and systems for sharing vehicles between fleets. Vehicle sharing services typically experience the most use during the weekend. Thus, many vehicles used by vehicle sharing services sit idle during the week. Meanwhile, vehicle rental companies experience the most demand during the week and their vehicles are underutilized during the week. The disclosed technology, in certain embodiments, provides systems and methods for sharing vehicles between a vehicle sharing entity and a vehicle renting entity. This allows the entities to lower fleet costs and obtain better fleet utilization by moving vehicles between fleets when one entity anticipates a spike in demand. For example, the ability for the vehicle sharing service to utilize a rental vehicle agency's excess weekend inventory will allow them to meet its strong weekend demand without the need for purchasing and maintaining additional vehicles.