In addition, the shareholder loan must carry a reasonable interest rate. I'm wanting to add an interest component to a long term loan liability account.A belowmarket loan is a loan which provides for no interest or interest at a rate below the federal rate that applies. For the shareholder, they need to fill out and send Form 1099INT to the corporation. Form 1099-INT outlines any interest paid on the loan. Current CalHFA interest rates and information on reserving a loan. This program offers loan guarantees to lenders for their loans to rural businesses.