The amortization expense of a bond issue cost (which is an asset) pertaining to a specific period of time or financial period. These expense appear in income statement with head "bond issue cost expenses"
Bond issue cost Costs and expenses which are necessary to make and compete the sales of bonds. Examples of these expenses are accounting, commissions, legal, underwriting, registration fees and charges
These expenses are of capital nature therefore they are recognized as intangible asset of an entity and amortize over the number of periods up to the maturity of a bond. Companies adopt different amortization methods suitable to their requirements and circumstances. For example straight line method of amortization, declining method, sum of digit etc.