The common name for the “Tax for Children Under Age 14 Who Have Investment Income of More Than $1,400.” The kiddie tax applies to a child’s investment income, such as interest, dividends, rents, and royalties and is imposed at the same marginal rate as his or her parents’ tax rate. “In 2008, the kiddie tax will be expanded to include dependent children under 19 and dependent college students under 24. The kiddie tax will apply to income in excess of $1,800 in 2008” (from TurboTax.Com).