California Code, Revenue and Taxation Code - RTC § 6423

(a) A purchaser certifying under subparagraph (B) of paragraph (4) of subdivision (c) of Section 6011 or subparagraph (B) of paragraph (4) of subdivision (c) of Section 6012 that he or she is entitled to either a direct refund or credit against his or her income tax for the federal excise tax paid shall do so in a form prescribed by the board.

(b) If the purchaser provides the certificate referred to in subdivision (a) and uses the fuel in a manner that does not entitle the purchaser to a direct refund or credit against his or her income tax for the federal excise tax paid or if the purchaser does not receive such a refund or credit, the purchaser shall be liable for sales or use tax measured by the amount of federal excise tax paid to the extent the seller has not remitted sales or use tax measured by that amount.  The certificate shall relieve the seller from liability for any sales or use tax due only if it is taken in good faith.

(c) Any person, including any officer or employee of a corporation, who certifies under subparagraph (B) of paragraph (4) of subdivision (c) of Section 6011 or subparagraph (B) of paragraph (4) of subdivision (c) of Section 6012 that he or she is entitled to either a direct refund or credit against his or her income tax for the federal excise tax paid on fuel when that person knows at the time of purchase that he or she shall not be entitled to the refund or credit is liable to the state for the amount of sales or use tax that would be due if he or she had not so certified.  In addition to the tax, interest, and other penalties, the person shall be liable to the state for a penalty of 10 percent of the tax or five hundred dollars ($500), whichever is greater, for purchases made for personal gain or to evade payment of taxes.

(d) Any person, including any officer or employee of a corporation, who, for the purpose of evading payment to the seller of a portion of the tax applicable to the transaction, certifies under subparagraph (B) of paragraph (4) of subdivision (c) of Section 6011 or subparagraph (B) of paragraph (4) of subdivision (c) of Section 6012 that he or she is entitled to either a direct refund or credit against his or her income tax for the federal excise tax paid on fuel when that person knows at the time of purchase that he or she is not entitled to such a refund or credit is guilty of a misdemeanor punishable as provided in Section 7153.