Cal. RTC § 8102

(a) The claimant of a refund shall present to the Controller a claim supported by the original invoice showing the purchase or other evidence of each purchase that is satisfactory to the Controller. The claim shall state the total amount of the fuel purchased by the claimant and the manner and the equipment in which the claimant has used the fuel. The claim shall state the total amount of motor vehicle fuel covered by the claim and if the motor vehicle fuel was exported, a statement that the claimant has proof of exportation. The claim shall state that the amounts claimed have not been previously refunded to the claimant and that there are no other claims outstanding for the amounts included in the current claim for refund. The claim shall not be under oath but shall contain, or be accompanied by, a written declaration that it is made under the penalties of perjury. If no original invoice was created, electronic invoicing shall be accepted as reflected by a computerized facsimile when accompanied by an original copy of the bill of lading or fuel manifest that can be directly tied to the electronic invoice.

(b) Each claim for refund under this section shall be made on a form prescribed by the Controller and shall be filed for a calendar year, except for claims relating to exportation of fuel. If, at the close of any of the first three quarters of the calendar year, more than seven hundred fifty dollars ($750) is refundable under this section with respect to any motor vehicle fuel used, sold, or exported during that quarter or any prior quarter during the calendar year, and for which no other claim has been filed, a claim may be filed for the quarterly period. To facilitate the administration of this section, the Controller may require the filing of claims for refund for other than yearly periods. Export claims may be filed at any time.