Cal. Rev. & Tax. Code § 7320

“Highway vehicle operator/fueler” includes:

(a)Any person that owns, operates, or otherwise controls a motor vehicle fuel-powered highway vehicle and delivers, or causes to be delivered, motor vehicle fuel or any liquid into the fuel tank of a motor vehicle fuel-powered highway vehicle; or

(b)Any person who sells motor vehicle fuel on which a claim for refund has been allowed, or who sells and delivers or causes to be delivered into the fuel tank of a motor vehicle fuel-powered highway vehicle any liquid on which tax has not been imposed.