Difference between a bond's face value and the proceeds received from the bond's sale, less the amount written off to expense as reported on the profit and loss statement--that is, amortized. The amount still to be expensed at any point is the unamortized bond discount. At the time of the bond's issuance, the corporation has two choices. It can immediately include the discounted amount plus costs associated with the bond's issuance--such as legal and registration costs. Or, the corporation may treat the total discount and expenses as a deferred charge. It will be reported as an asset and will be written off over the bond's life or by any other schedule the corporation finds expedient.

This definition is in context to Frauds and Scams. See more contextual defintions for Unamortized Bond Discount.