In corporate finance, capital structure refers to the mix of various forms of external funds, known as capital, used to finance a business. It consists of shareholders' equity, debt (borrowed funds), and preferred stock, and is detailed in the company's balance sheet. The larger the debt component is in relation to the other sources of capital, the greater financial leverage (or gearing, in the United Kingdom) the firm is said to have. Too much debt can increase the risk of the company and reduce its financial flexibility, which at some point creates concern among investors and results in a greater cost of capital. Company management is responsible for establishing a capital structure for the corporation that makes optimal use of financial leverage and holds the cost of capital as low as possible.
Capital structure is an important issue in setting rates charged to customers by regulated utilities in the United States. The utility company has the right to choose any capital structure it deems appropriate, but regulators determine an appropriate capital structure and cost of capital for ratemaking purposes.
