In California, courts will pierce the corporate veil when two requirements are met: 1) the Court finds unity of interests (the shareholders, or owners in the case of an LLC, treat the corporation as an alter ego) - this happens when shareholders treat the assets of the corporation or LLC as their own and/or use corporate funds to pay their private debts; and 2) the Court finds that allowing shareholders to dodge personal liability would sanction fraud or promote injustice. To answer these questions, courts look at numerous factors including: whether the shareholders/owners acted in bad faith; whether individual contracts were entered into with the intent of avoiding performance and hiding behind a corporate shield; whether assets have been diverted to the detriment of creditors; whether there is ownership and control of the entity by a few key individuals; whether the shareholders/owners and the corporation share the same office or business location; whether the shareholders/owners and the corporation share the same attorney; whether the shareholders/owners used the entity to procure labor, services and merchandise for others; whether the entity was adequately capitalized; whether corporate formalities were followed; and whether the result would be unjust should the court fail to pierce the corporate veil.
While California courts are generally reluctant to pierce the corporate veil, they are not afraid to apply the theory where the above factors evidence injustice. Entity shareholders and owners unsure about their personal protections should consult a business attorney.