If your available Child Tax Credit is greater than your tax liability, the Child Tax Credit can only reduce your tax bill to zero — you don’t get any unused portion of the credit back as a refund. However, you may be able to claim the Additional Child Tax Credit
To claim the Additional Child Tax Credit you must have a minimum of $2,500 of earned income to claim the ACTC. Earned income can come from salaries and wages, self-employment, and some disability payments.
Form 8812 is used to calculate your Additional Child Tax Credit. TurboTax will ask you a few simple questions about your dependents and income, calculate your credit, and fill in all of the right forms for you.
The credit will be reported on form 1040 line 28.