Toyota will test a new car-sharing system next year that lets users unlock doors and start cars with their smartphones.

The Smart Key Box system eliminates the need for a physical key. Toyota will test the system in San Francisco with the Getaround car-sharing service starting in January. A Toyota investment fund put money into Getaround this month.

Toyota says a user's phone will get codes to access the smart key box inside car-sharing vehicles. When the phone gets close to the vehicle, the codes are verified through the Bluetooth system.

Related: Virtual car keys coming in 2018

If the experiment is successful, Toyota may use the system in Japan for an unmanned car rental business.

Keyless car-sharing is not totally new. General Motors' Maven car-sharing system uses a mobile app to unlock cars and allow them to be started with the push-button ignition. Maven is in nine U.S. cities at present. The more pervasive ZipCar sharing service lets users access cars with a card, then use keys that are inside.

Toyota also is developing a system that lets an owner send car-sharing income to Toyota Financial Services to make lease payments.