Companies do not produce bicycles with VIN numbers, but most manufacturers engrave or stamp serial numbers under the bottom brackets of frames. Registries, such as the Bike Index, Bike Shepherd and many academic institution administrations, record bicycle information for preventative security and assistance with stolen bicycle recovery.
Cycle registries operate as free peer-to-peer Internet databases or commercial registries that provide the service for a fee. In the state of California, a law exists allowing municipalities to impose an annual vehicle registration surcharge for bicycles. Many registries supply decals for easy identification of registered bicycles. These decals are removal resistant and provide a visible theft deterrent. When a theft occurs, parties involved share identification details with relevant authorities or among the cycling community with the goal of finding the stolen bicycle.