Additional Child Tax Credit This credit is for certain individuals who get less than the full amount of the child tax credit. The additional child tax credit may give you a refund even if you do not owe any tax. How to claim the additional child tax credit. To claim the additional child tax credit, follow the steps below. Make sure you figured the amount, if any, of your child tax credit. See Claiming the Credit, earlier. Use Form 8812 to see if you can take the additional child tax credit only if you answered "Yes" on line 4 or line 5 of the Child Tax Credit Worksheet. If you have an additional child tax credit on line 13 of Form 8812, carry it to line 63 (Form 1040) or line 40 (Form 1040A). Taxable earned income. Generally, for purposes of the additional child tax credit, your taxable earned income is the amount on line 7 of Form 1040 or Form 1040A. See the instructions for Form 8812 to figure your taxable earned income.