California Code, Financial Code - FIN § 5651

(a) No certificate of approval of articles of incorporation of a proposed association having the same name as an association in existence in this state on the date an application is filed under Section 5401, or a name so nearly resembling it as to be likely to deceive, shall be issued by the commissioner, except to an association formed by the reincorporation, reorganization, or consolidation of the association with other associations, or upon the sale of the property or franchise of an association.  The commissioner may presume that the use of any word or words already adopted, appropriated, or used in its corporate name by any association then existing in this state, except the words “the,” “and,” “mutual,” “guarantee,” “building,” “loan,” “savings,” “association,” or “bank,” constitutes such similarity of names as to be likely to mislead the public.

(b) An association shall not adopt or change to a name that will result in unfair competition or public confusion, or be deceptive, scandalous, or otherwise unsuitable.