A document published by the Internal Revenue Service (IRS) that provides guidance on determining the child tax credit that can be claimed and how to calculate the amount of earned income to report when applying for the Additional Child Tax Credit. IRS Publication 972 provides more specialized information pertaining to the child tax credits found in Form 1040 and Form 8812.

IRS Publication 972 has a worksheet that helps determine if a child is eligible, and how much credit a taxpayer can take. The maximum amount that can be claimed for a qualifying child is $1,000, and must be claimed using Form 1040.

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Taxpayers must have a qualifying child in order to be eligible for the child tax credit. A qualifying child is under the age of 17, is claimed as a dependent on the taxpayer's return and is a U.S. citizen, resident alien or national. More information on residency requirements can be found in IRS Publication 519.