A key information sharing system includes a first user terminal carried by a first user of a vehicle, a second user terminal carried by a second user of the vehicle, and a server device configured to distribute key information to the first user terminal. The key information is used for a key system that determines whether to lock and unlock the vehicle, make the vehicle travel, and use a content providing device that provides digital contents in a vehicle cabin of the vehicle. The server device is configured to distribute the key information to which restricted function information is added, to the first user terminal. The restricted function information is information indicating that locking and unlocking of the vehicle and use of the content providing device are permitted but traveling of the vehicle is not permitted. The server device is configured to distribute the to the first user terminal.