Cal. Rev. & Tax. Code § 9351

Any person who places or causes to be placed fuel into a receptacle on a motor vehicle from which receptacle fuel is supplied for the propulsion of the vehicle, or who acquires fuel outside this state and uses the fuel for the propulsion of a motor vehicle within this state, is guilty of a misdemeanor unless that person is a vendor and collects the tax as provided under Section 8732 or 8736 or that person is a user who holds a valid use fuel tax permit, or is excluded from that requirement under Section 8608, and uses the fuel placed in the receptacle. He or she shall be fined for each offense not less than one hundred dollars ($100) and not more than one thousand dollars ($1,000), or be imprisoned for not exceeding six months in the county jail, or be subject to both fine and imprisonment in the discretion of the court.