Cal. Civ. Code § 1725

(a) Unless permitted under subdivision (c), no person accepting a negotiable instrument as payment in full or in part for goods or services sold or leased at retail shall do any of the following:
1. (1) Require the person paying with a negotiable instrument to provide a credit card as a condition of acceptance of the negotiable instrument, or record the number of the credit card.
2. (2) Require, as a condition of acceptance of the negotiable instrument, or cause the person paying with a negotiable instrument to sign a statement agreeing to allow his or her credit card to be charged to cover the negotiable instrument if returned as no good.
3. (3) Record a credit card number in connection with any part of the transaction described in this subdivision.
4. (4) Contact a credit card issuer to determine if the amount of any credit available to the person paying with a negotiable instrument will cover the amount of the negotiable instrument.
(b) For the purposes of this section, the following terms have the following meanings:
1. (1) “Check guarantee card” means a card issued by a financial institution, evidencing an agreement under which the financial institution will not dishonor a check drawn upon itself, under the terms and conditions of the agreement.
2. (2) “Credit card” has the meaning specified in Section 1747.02, and does not include a check guarantee card or a card that is both a credit card and a check guarantee card.
3. (3) “Negotiable instrument” has the meaning specified in Section 3104 of the Commercial Code.
4. (4) “Retail” means a transaction involving the sale or lease of goods or services or both, between an individual, corporation, or other entity regularly engaged in business and a consumer, for use by the consumer and not for resale.
(c) This section does not prohibit any person from doing any of the following:
1. (1) Requiring the production of reasonable forms of positive identification, other than a credit card, which may include a driver’s license or a California state identification card, or where one of these is not available, another form of photo identification, as a condition of acceptance of a negotiable instrument.
2. (2) Requesting, but not requiring, a purchaser to voluntarily display a credit card as an indicia of creditworthiness or financial responsibility, or as an additional identification, provided the only information concerning the credit card which is recorded is the type of credit card displayed, the issuer of the card, and the expiration date of the card. All retailers that request the display of a credit card pursuant to this paragraph shall inform the customer, by either of the following methods, that displaying the credit card is not a requirement for check writing:
  1. (A) By posting the following notice in a conspicuous location in the unobstructed view of the public within the premises where the check is being written, clearly and legibly: “Check writing ID: credit card may be requested but not required for purchases.”
  2. (B) By training and requiring the sales clerks or retail employees requesting the credit card to inform all check writing customers that they are not required to display a credit card to write a check.
3. (3) Requesting production of, or recording, a credit card number as a condition for cashing a negotiable instrument that is being used solely to receive cash back from the person.
4. (4) Requesting, receiving, or recording a credit card number in lieu of requiring a deposit to secure payment in event of default, loss, damage, or other occurrence.
5. (5) Requiring, verifying, and recording the purchaser’s name, address, and telephone number.
6. (6) Requesting or recording a credit card number on a negotiable instrument used to make a payment on that credit card account.
(d) This section does not require acceptance of a negotiable instrument whether or not a credit card is presented.
(e) Any person who violates this section is subject to a civil penalty not to exceed two hundred fifty dollars ($250) for a first violation, and to a civil penalty not to exceed one thousand dollars ($1,000) for a second or subsequent violation, to be assessed and collected in a civil action brought by the person paying with a negotiable instrument, by the Attorney General, or by the district attorney or city attorney of the county or city in which the violation occurred. However, no civil penalty shall be assessed for a violation of this section if the defendant shows by a preponderance of the evidence that the violation was not intentional and resulted from a bona fide error made notwithstanding the defendant’s maintenance of procedures reasonably adopted to avoid such an error. When collected, the civil penalty shall be payable, as appropriate, to the person paying with a negotiable instrument who brought the action or to the general fund of whichever governmental entity brought the action to assess the civil penalty.
(f) The Attorney General, or any district attorney or city attorney within his or her respective jurisdiction, may bring an action in the superior court in the name of the people of the State of California to enjoin violation of subdivision (a) and, upon notice to the defendant of not less than five days, to temporarily restrain and enjoin the violation. If it appears to the satisfaction of the court that the defendant has, in fact, violated subdivision (a), the court may issue an injunction restraining further violations, without requiring proof that any person has been damaged by the violation. In these proceedings, if the court finds that the defendant has violated subdivision (a), the court may direct the defendant to pay any or all costs incurred by the Attorney General, district attorney, or city attorney in seeking or obtaining injunctive relief pursuant to this subdivision.
(g) Actions for collection of civil penalties under subdivision (e) and for injunctive relief under subdivision (f) may be consolidated.