Meaning for U.S. Income Tax Purposes

For the average citizen in many countries, the term “income” is most relevant for its role in determining how much income tax a person must pay. In the United States, the Internal Revenue Service (IRS) is the executive agency in charge of collecting income taxes. The IRS implements and enforces the Internal Revenue Code (IRC), a set of laws passed by Congress.

For the purpose of taxing income under the IRC, the IRS relies on the definition of income provided in a 1955 U.S. Supreme Court case called Commissioner v. Glenshaw Glass Co., 348 U.S. 426 (1955). According to this case, taxpayers have “income” when they experience "instances of undeniable accessions to wealth, clearly realized, and over which the taxpayers have complete dominion." This means that a taxpayer has income for income tax purposes when he receives something of value (including money, property, securities, or anything else), the transfer is complete, and the taxpayer can control the thing of value.

This definition is helpful for a taxpayer trying to decide what constitutes income. However, there is another way of looking at income for income tax purposes. “Income” is a concept Congress has seized upon for allocating how much tax each member of society will pay. The system seeks to tax individuals in a way that is fair, or at least in a way that appears to be fair. By claiming to assign tax burdens according to how much “income” a person has, the system purports to tax all taxpayers evenly.