Let’s use an example of a husband and wife who do not “mix finances”. The wife owns the house solely in her name, and the husband has a business solely in his name with debts both personal and under the business. They carefully keep completely separate bank accounts, credit card accounts, etc.
If all debts are kept completely separate — i.e. the wife is not listed as an owner of the business; the wife has not agreed specifically to pay any of her husband’s personal or business loans, credit card balances or business expense debts; and if the wife has in no way encumbered her home to guarantee or secure any of the husband’s obligations — then the wife should have no liability should the husband die or become incapacitated.
Remember, the above statement is general in nature and assumes a complete separation of finances. Also remember, debt collectors may still attempt to force the spouse to pay (and in many cases will use all manner of influence to do so). But as a matter of law, debts can only be collected from the person making them, and legal options exist to ensure such separation.