Q: When a spouse has ownership in a highly profitable business, how can/do they hide/misrepresent assets?

A: Take Cash or open bank accounts without your knowledge,

A: In my experience, the most common ways are for the spouse to use the business entity to purchase and own assets which are unrelated to any legitimate business purpose of the entity and for the spouse to cause the business entity to retain earnings that the spouse is entitled to for providing personal services to the business entity.

A business entity, such as a closely-held corporation, partnership, or limited liability company is a separate legal entity from the spouse. Operated properly, the assets and liabilities of that business entity belong to that legal entity and not to the individual spouse or marital estate of the parties. Only the spouse's ownership interest in the entity is part of the marital estate if that interest was acquired during the marriage.

When a spouse already owns an interest in a business entity at the time of marriage, that interest is and often remains the separate property of that spouse. Any assets acquired by the business entity (e.g. cars, real estate, equipment, etc.) during the marriage is property of the entity which, in turn, is the separate property of the spouse. Some spouses use the business entity to defraud the marital estate by acquiring assets in the entity's name but which they use for personal purposes rather than for the business purpose of the entity. It is often difficult to prove facts to convince the court to disregard the legal entity (sometimes called "piercing the corporate veil") so that it can divide assets owned by the entity as part of the division of the parties' marital estate.