Any money lent to your corporation should be documented by way of a debt instrument (i.e. a promissory note) and secured. A mortgage would be used for any of the corporation’s property that is comprised of real estate. For all other property, a general security agreement would be used. If a bank or other lender needs a priority security position for these assets, the shareholder’s interest in them can be postponed or subordinated. In that case, the shareholder’s interest would still be that of a secured creditor, even though subordinate to the institutional lender.