The Fair Tax Act (H.R. 25/S. 122) is a bill in the United States Congress for changing tax laws to replace the Internal Revenue Service (IRS) and all federal income taxes (including Alternative Minimum Tax), payroll taxes (including Social Security and Medicare taxes), corporate taxes, capital gains taxes, gift taxes, and estate taxes with a national retail sales tax, to be levied once at the point of purchase on all new goods and services. The proposal also calls for a monthly payment to households of citizens and legal resident aliens (based on family size) as an advance rebate of tax on purchases up to the poverty level.

Supporters argue that a consumption tax, such as the FairTax, would have a positive impact on available capital (through deferred taxation on investment), increased U.S. international competitiveness (border tax adjustment in global trade), incentives for international business to locate in the U.S., increased economic growth, and ease of tax compliance. The plan may increase cost transparency for funding the federal government and supporters believe it would have positive effects on civil liberties, the environment, and advantages with taxing illegal activity and illegal immigrants. Because the FairTax plan would remove taxes on income, tax deductions would have no meaning or value, which concerns some lawmakers about losing this method of social incentive. There are also concerns regarding the repeal of the Sixteenth Amendment, transition effects on after-tax savings, impact to the income tax industry, incentives on credit use, and the loss of tax advantages to state and local bonds.