Adding shareholders to a California corporation involves selling corporate stock. When someone receives shares of stock, they officially become a shareholder.Section 305 of the California Corporations Code sets forth the rules for filling vacancies on the board of directors. Learn the steps to incorporate your business in California, including filing registration and tax paperwork, drafting corporate documents, and issuing stock. Law Advocate Group, LLP. How to Elect and Remove Corporate Directors in CA? The forms constitute the bulk of those necessary for the day to day keeping of the corporate formalities in a California corporation. A California corporation with three or more shareholders must have at least three directors. Three director minimum – Corporations with more than two shareholders must have at least three directors. Maximum Number of Directors in a Flexible Board.