Gross income is the starting point for calculating a taxpayer's tax liability. The definition of gross income as "all income from whatever source derived" is perhaps the most well-known definition in the tax law. Under this definition, unless there is an exception in the law, the U.S. government considers all income taxable. Therefore, prizes and awards, cash and noncash payments for goods and services, payments made in trade or barter (such as car repairs traded for tax preparation services), and illegal income not generally reported to the IRS are all still taxable income. What was one of the most important things that you learned in this chapter about reporting gross income?