California Code, Government Code - GOV § 84310

(a) A candidate, candidate controlled committee established for an elective office for the controlling candidate, political party committee, or slate mailer organization shall not expend campaign funds, directly or indirectly, to pay for telephone calls that are similar in nature and aggregate 500 or more in number, made by an individual, or individuals, or by electronic means and that advocate support of, or opposition to, a candidate, ballot measure, or both, unless during the course of each call the name of the candidate, candidate controlled committee established for an elective office for the controlling candidate, political party committee, or slate mailer organization that authorized or paid for the call is disclosed to the recipient of the call.  Unless the organization that authorized the call and in whose name it is placed has filing obligations under this title, and the name announced in the call either is the full name by which the organization or individual is identified in any statement or report required to be filed under this title or is the name by which the organization or individual is commonly known, the candidate, candidate controlled committee established for an elective office for the controlling candidate, political party committee, or slate mailer organization that paid for the call shall be disclosed.  This section does not apply to telephone calls made by the candidate, the campaign manager, or individuals who are volunteers.

(b) Campaign and ballot measure committees are prohibited from contracting with any phone bank vendor that does not disclose the information required to be disclosed by subdivision (a).

(c) A candidate, committee, or slate mailer organization that pays for telephone calls as described in subdivision (a) shall maintain a record of the script of the call for the period of time set forth in Section 84104.  If any of the calls qualifying under subdivision (a) were recorded messages, a copy of the recording shall be maintained for that period.

(d) This section does not apply to a telephone call that is paid for by an independent expenditure.