CA Gov't Code Section 6166

Any state agency accepting payment by a means of credit card, whether pursuant to this chapter or Section 19005 of the Revenue and Taxation Code, shall, when sending a billing statement, notify each payer permitted to make payment to that agency by means of a credit card of his or her option of making payment by means of a credit card. Each state agency that sends a billing statement to an individual who is allowed to make payment to that agency by means of a credit card shall provide either of the following on that statement or on a document provided with the statement:

(a)

A designated space on the payment form upon which the payer can provide a credit card number, expiration date, and signature.

(b)

Complete instructions as to the procedure, by means of telephone or otherwise, that the payer must follow in order to pay by means of a credit card.