It can depend on your income.
If your income is too high, the income limitations begin to phase out the credit. If your income is too low, your credit can be effected as well.
See the following income limitations from the IRS:
The credit is limited if your modified
adjusted gross income is above a certain amount. The amount at which this
phase-out begins varies depending on your filing status. For married taxpayers
filing a joint return, the phase-out begins at $110,000. For married taxpayers
filing a separate return, it begins at $55,000. For all other taxpayers, the
phase-out begins at $75,000. In addition, the Child Tax Credit is generally
limited by the amount of the income tax you owe as well as any alternative minimum
tax you owe. The credits are phased out by 50 dollars for every 1,000 dollars that you are over the threshold amount. If your income is 20,000 dollars over the threshold, the credits are completely phased out.
If your income is on the other side of the income range, the additional child tax credit is calculated by subtracting 3,000 dollars from your earned income and multiplying that amount by 15%. The additional child tax credit is the lower of the total unused child tax credit or the calculated amount (explained above). For example, if your earned income is only 7,000 dollars and you have 3 kids, your refundable additional child tax credit would only be 600 dollars (7,000 dollars - 3,000 dollars = 4,000, 4,000 X 15% = 600 dollars, 3,000 total possible child tax credits > 600 dollars). In this case, the child tax credit is lower because the income was too low.
