California Code, Revenue and Taxation Code - RTC § 60161

(a) Every person before becoming a qualified highway vehicle operator shall apply to the board for a license authorizing the person to engage in business as a qualified highway vehicle operator. A license shall be issued only to a person who is qualified to use dyed diesel fuel on the highway by the Internal Revenue Service under Section 48.4082-4 of Title 26 of the Code of Federal Regulations.

(b) If the person is already licensed as an exempt bus operator, government entity, or interstate user, the person does not need a separate qualified highway vehicle operator's license.