Updated October 18, 2026. Quick answer: Line 4 counts the qualifying children for the child tax credit and line 6 counts other dependents. You take both counts from the boxes checked in the Dependents section of Form 1040. Lines 5, 7 and 8 are arithmetic on those counts.
Line 4: qualifying children
The form’s caption is “Number of qualifying children under age 17 with the required social security number”. The instructions say “Add the number of “Child tax credit” boxes checked in row (7) of the Dependents section on Form 1040 or 1040-SR” and then “enter the result on line 4.”
Who counts as a child here: “To claim a child for the CTC and ACTC, the child must be your dependent, under age 17 at the end of 2025”. The number requirement reads “If you have a qualifying child who does not have a valid SSN, you can’t use the child to claim the CTC or ACTC”. Claiming a grandchild is covered at claiming your grandchild as a dependent.
Line 6: other dependents
The caption reads “Number of other dependents, including any qualifying children who are not under age 17 or who do not have the required social security number”. The instructions say “Add the number of “Credit for other dependents” boxes checked in row (7) of the Dependents section on Form 1040 or 1040-SR” and “enter the result on line 6.”
The form adds a caution: “Do not include yourself, your spouse, or anyone who is not a U.S. citizen, U.S. national, or U.S. resident alien.” It continues “Also, do not include anyone you included on line 4.”
Checking the right box
Both line instructions repeat one rule: “You can’t check both the child tax credit box and the credit for other dependents box for the same person.” The dependents themselves are set up on the return, which the Form 1040 line by line page covers.
Lines 5, 7 and 8: the arithmetic
Line 5 says “Multiply line 4 by $2,200”. Line 7 says “Multiply line 6 by $500”. Line 8 says “Add lines 5 and 7”. Line 8 is the starting amount before the income reduction.
Computed illustration, not an IRS example: with 2 qualifying children on line 4 and 1 other dependent on line 6, line 5 is 2 x $2,200 = $4,400, line 7 is 1 x $500 = $500, and line 8 is computed as $4,400 + $500 = $4,900. Your own counts will differ.
Where the number comes from
The counts on lines 4 and 6 come from the Dependents section on page 1 of your Form 1040. The instructions on the Form 8332 page explain when a release of a claim moves the credit to the other parent.
Where it goes next
Line 8 is tested on line 12, where the form asks “Is the amount on line 8 more than the amount on line 11?” Line 4 also feeds the later Parts: “The number of children you use for this line is the same as the number of children you used for line 4.” See the lines 9 to 14 page for the next step.
Edition and line numbers
This page reads the 2025 Schedule 8812 (Form 1040), Credits for Qualifying Children and Other Dependents and its 2025 instructions, the current files irs.gov served on 2026-10-18. They are the files for the tax year 2025 return, filed in 2026. The form’s own header says “Attach to Form 1040, 1040-SR, or 1040-NR.” Check the tax year printed on the form you are filling in and use the line numbers on that year’s form, because a different year’s form can number or word its lines differently.
Common mistakes
- Counting a person on both lines. The form says “Also, do not include anyone you included on line 4.”
- Counting a child who turned 17 during the year. The instructions give an example: “because the child was not under age 17 at the end of 2025.”
- Counting a spouse or yourself on line 6. The form says “Do not include yourself, your spouse, or anyone who is not a U.S. citizen, U.S. national, or U.S. resident alien.”
Related: claiming your grandchild as a dependent, Form 1040 line by line, Form 8332, and child tax credit.
Sources
- Instructions for Schedule 8812 (Form 1040), Credits for Qualifying Children and Other Dependents (2025): https://www.irs.gov/pub/irs-pdf/i1040s8.pdf
- Schedule 8812 (Form 1040), Credits for Qualifying Children and Other Dependents (2025): https://www.irs.gov/pub/irs-pdf/f1040s8.pdf
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.