Cal. Bus. & Prof. Code § 5056

Any person who has received from the board a certificate of public accountant may, subject to Section 5051, be styled and known as a “public accountant” and may also use the abbreviation “P.A.” No other person, except a firm registered under this chapter, shall assume or use that title, designation, or abbreviation or any other title, designation, sign, card, or device tending to indicate that the person using it is a public accountant.