Bus. & Prof. Code, § 16721

Recognizing that the California Constitution prohibits a person from being disqualified from entering or pursuing a business, profession, vocation, or employment because of sex, race, creed, color, or national or ethnic origin, and guarantees the free exercise and enjoyment of religion without discrimination or preference; and recognizing that these and other basic, fundamental constitutional principles are directly affected and denigrated by certain ongoing practices in the business and commercial world, it is necessary that provisions protecting and enhancing a person’s right to enter or pursue business and to freely exercise and enjoy religion, consistent with law, be established.

(a) No person within the jurisdiction of this state shall be excluded from a business transaction on the basis of a policy expressed in any document or writing and imposed by a third party where that policy requires discrimination against that person on the basis of any characteristic listed or defined in subdivision (b) or (e) of Section 51 of the Civil Code or on the basis that the person conducts or has conducted business in a particular location.

(b) No person within the jurisdiction of this state shall require another person to be excluded, or be required to exclude another person, from a business transaction on the basis of a policy expressed in any document or writing that requires discrimination against that other person on the basis of any characteristic listed or defined in subdivision (b) or (e) of Section 51 of the Civil Code or on the basis that the person conducts or has conducted business in a particular location.

(c) Any violation of any provision of this section is a conspiracy against trade.

(d) Nothing in this section shall be construed to prohibit any person, on this basis of his or her individual ideology or preferences, from doing business or refusing to do business with any other person consistent with law.