Cal. Rev. & Tax. Code § 8610

“Vendor” includes every person who sells fuel in this state and places, or causes to be placed, the fuel into any receptacle on a motor vehicle from which receptacle fuel is supplied for the propulsion of the vehicle.

“Vendor” does not include a person who places the fuel, or causes the fuel to be placed, into a receptacle on a privately operated passenger motor vehicle with respect to which the annual flat rate fuel tax described in Section 8651.7 has been paid for the current year and to which is attached the current prescribed identification emblem.