Cal. Rev. & Tax. Code § 7364

The tax specified in Section 7360 is imposed as a backup tax as follows:

(a)On the delivery into the fuel tank of a motor vehicle fuel-powered highway vehicle of:

(1)Any motor vehicle fuel on which a claim for refund has been allowed; or

(2)Any liquid on which tax has not been imposed by this part, Part 3 (commencing with Section 8601), or Part 31 (commencing with Section 60001).

(b)On the sale of any motor vehicle fuel on which a claim for refund has been allowed.

(c)On the sale and delivery into the fuel tank of a motor vehicle fuel-powered highway vehicle of any liquid on which tax has not been imposed by this part, Part 3 (commencing with Section 8601), or Part 31 (commencing with Section 60001).