Passive income is earnings derived from a rental property, limited partnership or other enterprise in which a person is not actively involved. As with active income, passive income is usually taxable. However, it is often treated differently by the Internal Revenue Service (IRS). Portfolio income is considered passive income by some analysts, so dividends and interest would therefore be considered passive.
Residual income is calculated as net income less a charge for the cost of capital. The charge is known as the equity charge and is calculated as the value of equity capital multiplied by the cost of equity or the required rate of return on equity. Given the opportunity cost of equity, a company can have positive net income but negative residual income.