California Code, Business and Professions Code - BPC § 5060

(a) No person or firm may practice public accountancy under any name which is false or misleading.

(b) No person or firm may practice public accountancy under any name other than the name under which the person or firm holds a valid permit to practice issued by the board.

(c) Notwithstanding subdivision (b), a sole proprietor may practice under a name other than the name set forth on their permit to practice, provided the name is registered by the board, is in good standing, and complies with the requirements of subdivision (a).

(d) The board may adopt regulations to implement, interpret, and make specific the provisions of this section including, but not limited to, regulations designating particular forms of names as being false or misleading.