Cal. Rev. & Tax. Code § 7402

(a) The certificate to be provided by a buyer of gasoline blendstocks consists of a statement that is signed under penalty of perjury by a person with authority to bind the buyer. A new certificate must be given if any information in the current certificate changes. The certificate may be included as part of any business records normally used to document a sale. The certificate expires on the earliest of the following dates:
1. (1) The date one year after the effective date of the certificate.
2. (2) The date a new certificate is provided by the buyer to the seller.
(b) An exemption certificate for gasoline blendstocks that states that the blendstocks will not be used to produce finished gasoline shall contain that information and be in the form as the board may prescribe.