The amount of Child Tax Credit on line 19 is limited by the amount of tax owed, shown on line 16. As the Child Tax Credit is not refundable, when the amount on line 16 is zero, there is no credit to be entered on line 19.
Certain clients may qualify to receive the difference in the form of the Additional Child Tax Credit, which is calculated on Form 8812.
This information applies to all years, please refer to the IRS website for more information.
Solution Articles:
Sch 8812 - Additional Child Tax Credit