• HISTORICAL DEVELOPMENT
• THE TAX COLLECTION PROCESS
• BUSINESS OBLIGATIONS
• RECENT TRENDS
• FURTHER READING:

The Internal Revenue Service (IRS), part of the U.S. Department of the Treasury, is mandated by federal law to enforce the tax laws of the United States. In addition to collecting income tax from individuals and corporations—the largest source (55 percent) of the government's income—the IRS also collects such major revenues as Social Security taxes, excises (taxes on commodities), gift taxes, and estate taxes. Internal revenues derived from the sale of alcohol, tobacco, and firearms are no longer collected by the IRS.

HISTORICAL DEVELOPMENT

For the most part, the...