Schedule 8812 (Form 1040): Additional Child Tax Credit – 2021 Tax Year
What the Form Is For
Schedule 8812 is the IRS form used to calculate child tax credits and reconcile advance child tax credit payments received during 2021. For the 2021 tax year specifically, this schedule served a unique dual purpose due to the American Rescue Plan Act's temporary enhancements to the Child Tax Credit program.
The form helps you determine three different types of credits. First, the Refundable Child Tax Credit (RCTC), which applies to taxpayers who had a principal place of residence in the United States for more than half of 2021 or were bona fide residents of Puerto Rico. This credit is fully refundable, meaning you can receive it even if you owe no tax. Second, the Nonrefundable Child Tax Credit (NCTC) and Additional Child Tax Credit (ACTC), which work together for taxpayers who don't meet the residency requirements—the NCTC reduces tax liability, while the ACTC provides a refundable portion. Third, the Credit for Other Dependents (ODC), which provides up to $500 for qualifying dependents who don't qualify for the child tax credit.
For 2021, the child tax credit was enhanced significantly. Children under age 6 at the end of 2021 qualified for up to $3,600, while children ages 6 through 17 qualified for up to $3,000. This was a temporary expansion from the standard $2,000 per child credit. Additionally, many eligible families received advance payments—monthly checks from July through December 2021 totaling half of their estimated credit. Schedule 8812 is where you reconcile these advance payments with your actual credit amount when filing your return.
The form also handles situations where you received more in advance payments than you're entitled to claim. Depending on your income level, you may have repayment protection that reduces or eliminates the amount you need to pay back.
When You'd Use It
You must file Schedule 8812 with your Form 1040, 1040-SR, or 1040-NR if you're claiming the child tax credit, additional child tax credit, or credit for other dependents. This includes virtually everyone who claims a qualifying child under age 18 or other qualifying dependents on their 2021 return.
The form is absolutely required if you received advance child tax credit payments during 2021, even if your situation changed and you're no longer eligible for the credit. Failing to reconcile these advance payments will delay processing of your return. You'll need Letter 6419, which the IRS mailed in January 2022 showing your total advance payment amount and the number of qualifying children used to calculate those payments. If you're married filing jointly, both spouses receive separate letters, and you must add the amounts together.
You should also file Schedule 8812 if your 2021 circumstances changed from 2020 in ways that affect the credit. Common changes include a new child being born or adopted, gaining or losing custody of a child, changes in filing status (such as getting married or divorced), significant income increases or decreases, or changes in where you lived during the year.
For late or amended returns, the timing rules are important. If you're filing after the original deadline and claiming the child tax credit or additional child tax credit, you must still include Schedule 8812 regardless of when you file. However, there's a critical requirement for taxpayer identification numbers: you, your spouse, and qualifying children must have had valid Social Security Numbers or Individual Taxpayer Identification Numbers issued on or before the due date of your return (including extensions). You cannot claim these credits on an amended return if these identification numbers weren't valid by the original deadline. For the credit for other dependents, dependents can have an SSN, ITIN, or Adoption Taxpayer Identification Number issued by the due date.
If you need to file Form 1040-X to amend your 2021 return for child tax credit issues, you generally have three years from the date you filed your original return or two years from the date you paid the tax (whichever is later) to claim additional refunds. Amended returns can be filed electronically for 2021 returns.
Key Rules or Details for 2021
Child Eligibility Requirements
For the enhanced child tax credit and additional child tax credit, your qualifying child must be under age 18 at the end of 2021, claimed as your dependent, and meet all dependency requirements in the Form 1040 instructions. The child must be a U.S. citizen, U.S. national, or U.S. resident alien. Critically, the child must have a Social Security Number valid for employment that was issued before the due date of your return. Adopted children always qualify as your own child, including those lawfully placed with you for legal adoption.
Age Categories Matter
The credit amount depends on the child's age. Children under age 6 at year-end qualify for the full $3,600 credit. Children ages 6 through 17 qualify for $3,000. Children who turned 18 by December 31, 2021, don't qualify for the child tax credit but may qualify for the $500 credit for other dependents instead.
Residency Requirements
Two paths exist for 2021. Under Box A, you qualify for the fully refundable child tax credit if you (or your spouse if filing jointly) had a principal place of residence in the United States for more than half of 2021. Your main home can be any location where you regularly live—house, apartment, mobile home, shelter, or temporary lodging—and doesn't need to be the same physical location all year. Temporary absences for illness, education, business, or vacation don't affect this requirement. U.S. military personnel stationed outside the United States on extended active duty automatically satisfy this requirement. Under Box B, you also qualify if you were a bona fide resident of Puerto Rico, which requires meeting specific presence and tax home tests.
Income Phaseouts
The enhanced portion of the credit begins phasing out at modified adjusted gross income (MAGI) of $150,000 for married filing jointly and qualifying widow(er), $112,500 for head of household, and $75,000 for other filing statuses. The credit reduces by $50 for each $1,000 (or fraction thereof) your income exceeds these thresholds.
Advance Payment Reconciliation
If you received advance payments totaling more than your actual credit amount, you may need to repay some or all of the excess. However, repayment protection exists based on income. Full repayment protection applies if your MAGI is at or below $60,000 (married filing jointly), $50,000 (head of household), or $40,000 (single filers). The protection amount equals $2,000 per excess qualifying child—children the IRS counted for your advance payments but who you can't claim on your 2021 return. Protection phases out gradually until it reaches zero at MAGI of $120,000 (married filing jointly), $100,000 (head of household), or $80,000 (single filers).
Credit for Other Dependents
This $500 nonrefundable credit applies to dependents who don't qualify for the child tax credit. The dependent must be your qualifying dependent, cannot be used for the child tax credit, and must be a U.S. citizen, U.S. national, or U.S. resident alien. Common examples include children age 18 or older, qualifying relatives like parents or siblings you support, or children without valid Social Security Numbers who have ITINs or ATINs.
Step-by-Step (High Level)
Part I-A: Initial Information
Start by counting your qualifying children and dependents. On line 4a, enter the total number of qualifying children under age 18 with valid SSNs by checking the "child tax credit" box in the Dependents section of Form 1040. On line 4b, count how many of these children were under age 6 at year-end. Line 4c automatically calculates the remainder. On line 6, enter the number of dependents qualifying for the credit for other dependents by checking their boxes on Form 1040.
Line 5 requires the Line 5 Worksheet, which calculates your initial credit amount before phaseouts. This multiplies children under 6 by $3,600 and other qualifying children by $3,000, then reduces this by $2,000 per qualifying child to isolate the enhanced portion. The worksheet then applies the income phaseout based on your filing status and modified AGI from line 11 of Form 1040.
Determining Your Path
On line 13, check Box A if you had a main home in the United States for more than half of 2021, or check Box B if you were a bona fide resident of Puerto Rico. This determination is crucial because it directs you to complete either Part I-B (if you check a box) or Part I-C (if you don't).
Part I-B: RCTC/ODC Path (Box A or B Checked)
This simplified path is for taxpayers meeting residency requirements. Line 14c uses Credit Limit Worksheet A to calculate any credit for other dependents, which cannot exceed your tax liability minus certain other credits. Line 14f is where you enter your total advance child tax credit payments from Letter 6419. If married filing jointly, add both spouses' Letter 6419 amounts. Line 14g shows your refundable child tax credit after subtracting advance payments. If negative, you received excess payments and must complete Part III to determine repayment.
Part I-C: NCTC/ACTC/ODC Path (No Box Checked)
Taxpayers without qualifying U.S. residency follow this path, which mirrors pre-2021 rules. Line 15a uses Credit Limit Worksheet A to determine your nonrefundable credit amount based on tax liability. Line 15c requires completing Parts II-A through II-C to calculate additional child tax credit if your total credit exceeds the nonrefundable portion. Line 15e enters advance payments from Letter 6419.
Parts II-A, II-B, II-C: Additional Child Tax Credit Calculation
These sections apply only to taxpayers completing Part I-C who have earned income and whose total credit exceeds their nonrefundable credit amount. You'll calculate your earned income (wages, salaries, self-employment income), apply the ACTC formula which is generally 15% of earned income over $2,500, and determine the refundable portion limited to $1,400 per qualifying child. Credit Limit Worksheet B may be required if you're claiming certain other credits like the adoption credit or mortgage interest credit.
Part III: Excess Advance Payment Calculation
Complete this only if line 14g shows a negative number. This section calculates how much excess payment you must repay after applying repayment protection. The worksheet factors in your MAGI, filing status, and the number of qualifying children to determine your protection amount.
Common Mistakes and How to Avoid Them
Advance Payment Amount Errors
The most common mistake in 2021 was entering the wrong advance payment amount on line 14f or 15e. This occurs when taxpayers misread Letter 6419, forget to add both spouses' amounts when filing jointly, or estimate the amount instead of using the letter. Always locate Letter 6419 before starting your return. If married filing jointly, both spouses received separate letters—you must add both amounts. If you can't find your letter, check your IRS online account at IRS.gov or call 800-908-4184. Never guess this amount, as mismatches between what you report and IRS records cause automatic delays.
Age Calculation Mistakes
Parents frequently miscalculate whether their child was under age 6 or under age 18 at the end of 2021. The rule is simple: the child's age on December 31, 2021, determines the category. A child who turned 6 during 2021 is not "under age 6"—they qualify for the $3,000 credit, not $3,600. Similarly, a child who turned 18 on or before December 31, 2021, doesn't qualify for any child tax credit, only the $500 credit for other dependents.
Residency Requirement Confusion
Many taxpayers complete the wrong part of the form because they misunderstand the Box A residency requirement. Having a main home in the United States for more than half the year doesn't mean you were physically present every single day—temporary absences for vacation, education, or business don't count against you. However, if you lived abroad for work for seven months, you wouldn't meet this test. Military personnel stationed overseas always meet the requirement. If you're unsure, err on the side of checking Box A if your permanent home base was in the U.S., even if you traveled extensively.
Invalid or Missing Social Security Numbers
A qualifying child must have an SSN valid for employment issued before your return's due date (including extensions). ATINs and ITINs don't qualify for the child tax credit—only the credit for other dependents. If your child has an ITIN but not an SSN, don't check the "child tax credit" box; instead, check the "credit for other dependents" box. If your child was born and died in 2021 without receiving an SSN, attach the birth and death certificates showing the child was born alive.
Failing to Attach the Schedule
Some taxpayers calculate the credit but forget to attach Schedule 8812 to their return. Form 1040 line 19 (for the 2021 form) requires this schedule as support for the credit amount. Without it, your return is incomplete and processing will be delayed.
Double-Claiming Dependents
If you share custody of a child, only one parent can claim them each year. The advance payments in 2021 went to whoever claimed the child on their 2020 (or 2019) return. If the other parent claims the child for 2021, you must report this in Part III and repay your advance payments. Discuss with your co-parent before filing to avoid both of you claiming the same child, which triggers IRS rejection of the second return filed.
Math and Worksheet Errors
The Line 5 Worksheet and Credit Limit Worksheets involve multiple calculations. Common errors include forgetting to round income up to the next multiple of $1,000 when calculating phaseouts, using the wrong income threshold for your filing status, or incorrectly multiplying children by dollar amounts. Use tax software when possible, which automates these calculations. If preparing by hand, double-check each line and use a calculator rather than mental math.
What Happens After You File
Processing Timeframes
If you claim the additional child tax credit, federal law prohibits the IRS from issuing your refund before mid-February. For 2021 returns filed in early 2022, this meant refunds couldn't be released until mid-February 2022 at the earliest. This delay applies to your entire refund, not just the ACTC portion. Most taxpayers who e-filed with direct deposit and had no issues received refunds by early March 2022. Paper returns or returns with errors took significantly longer—often 12 to 16 weeks during the 2022 filing season due to IRS processing backlogs.
IRS Review and Corrections
The IRS reviews Schedule 8812 carefully because of the complex advance payment reconciliation. If you made an error calculating your credit amount or entering advance payments, the IRS will recalculate the correct amount and adjust your return automatically. You do not need to file an amended return if you made an honest mistake. The IRS will send you a notice (often a CP12 or similar) explaining the change and showing your corrected refund amount or balance due. Processing takes longer when corrections are needed—typically several additional weeks beyond normal processing times.
Refund Tracking
You can check your refund status using the "Where's My Refund?" tool at IRS.gov or the IRS2Go mobile app. Information typically appears within 24 hours of e-filing or four weeks after mailing a paper return. The tool shows three stages: return received, refund approved, and refund sent. During peak filing season, the tool may show "processing" for several weeks, which is normal for returns claiming ACTC.
Repayment of Excess Advance Payments
If Part III shows you owe repayment of excess advance payments, this amount appears as additional tax on Schedule 2 (Form 1040), line 6, which flows to Form 1040 and either reduces your refund or increases your balance due. If you owe more than expected and cannot pay in full, the IRS offers payment plans. You can set up an installment agreement online at IRS.gov/payments or by calling the number on any balance due notice. Short-term payment plans (120 days or less) have no setup fee. Long-term plans have fees that vary based on how you pay and your income level.
Verification and Audits
Returns claiming child tax credits face higher scrutiny due to fraud concerns. The IRS may send notices requesting proof of your child's relationship to you, their residency in your home, or verification of your advance payment amount. Common requests include school records, medical records showing your address, or Form 3115 from your health insurance. Respond to these notices by the deadline shown (typically 30 days) with copies—never originals—of requested documents. Failure to respond can result in credit denial.
Economic Impact on Benefits
Your refund from the additional child tax credit cannot be counted as income when determining eligibility for federal benefits programs like Medicaid, SNAP (food stamps), SSI, or TANF. The refund also cannot be counted as a resource for at least 12 months after you receive it. This protection applies to advance payments as well. Check with your local benefits coordinator if you have questions about how your refund might affect state or local programs.
FAQs
Can I claim the child tax credit if my child doesn't have a Social Security Number yet?
For the child tax credit or additional child tax credit, your child must have a Social Security Number valid for employment issued before your return's due date, including extensions. If your child only has an Individual Taxpayer Identification Number (ITIN) or Adoption Taxpayer Identification Number (ATIN), you cannot claim them for the child tax credit. However, you can claim the $500 credit for other dependents instead. If you applied for your child's SSN before the deadline and it's being processed, you may need to file for an extension until the SSN is issued. For newborns, apply for the SSN at the hospital or immediately after birth to avoid this issue.
What should I do if my Letter 6419 shows a different number of children than I'm claiming on my 2021 return?
This situation is common when custody changes, a child is born or adopted during 2021, or a child moves out of your home. Enter the exact advance payment amount from Letter 6419 on line 14f or 15e—don't adjust it based on your current situation. Then complete the rest of Schedule 8812 based on the number of qualifying children you actually have for 2021. If you're claiming fewer children than the IRS counted for advance payments, you'll calculate a repayment amount in Part III, though repayment protection may reduce or eliminate what you owe. If you're claiming more children than received advance payments for, you'll receive the additional credit amount as part of your refund.
My spouse and I both received Letter 6419, but we're divorced now. How do we each report advance payments?
If you were married when advance payments were sent but divorced before filing 2021 returns, each of you reports only your own Letter 6419 amount on your separate returns. Do not split the payment amount differently or combine both letters. Each person enters their own Letter 6419 figure and claims only the children who qualify on their individual return. The parent who doesn't claim the children for 2021 will need to repay their advance payments in Part III, subject to repayment protection based on their individual income.
What happens if someone else claimed my child before I could file, but I'm the custodial parent?
When the same child's Social Security Number appears on two returns, the IRS rejects the second return filed electronically. You'll need to file a paper return by mail claiming your child. Include all supporting documentation proving the child lived with you for more than half of 2021—school records, medical records, daycare statements, or other documents showing your address as the child's residence. The IRS will send letters to both filers asking for proof. The person who cannot substantiate their claim must file an amended return removing the child. This process typically takes several months to resolve.
I used the Child Tax Credit Non-filer Sign-up Tool in 2020. How does this affect my 2021 return?
If you used the Non-filer Tool to register for advance child tax credit payments but didn't file a 2020 tax return, you'll receive Letter 6419 showing your advance payments. When e-filing your 2021 return, you'll be asked for your "prior-year AGI" to verify your identity. Since you didn't file a 2020 return, enter "$1" (one dollar) as your prior-year AGI. If you enter the wrong amount, your e-file will be rejected, and you'll need to resubmit using "$1" or file a paper return.
My advance payment amount on Letter 6419 doesn't match what I received. Which number should I use?
Always use the amount shown in Box 1 of Letter 6419 on your tax return, even if you believe it's incorrect. This is the official IRS record of payments sent to you. If the letter is truly wrong—for example, it doesn't include a payment you know was issued, or includes amounts you returned—you should call the IRS at 800-908-4184 or check your online account at IRS.gov before filing. If the IRS records match the letter but you think you received different amounts, remember that payments could have been offset against other debts, sent to an old address, or deposited to a closed bank account. Resolve these discrepancies before filing, as mismatches between what you report and IRS records cause automatic processing delays.
Do I need to file Schedule 8812 even if I opted out of advance payments?
Yes, if you're claiming the child tax credit, additional child tax credit, or credit for other dependents, you must file Schedule 8812 regardless of whether you received advance payments. If you opted out or received no advance payments, you'll enter "$0" on line 14f or 15e, and the full credit amount will be calculated as part of your refund or applied to your tax liability. The schedule is required to claim these credits even when no reconciliation of advance payments is needed.
Note: All information is based on official IRS sources including the 2021 Instructions for Schedule 8812, IRS guidance on advance Child Tax Credit payments, and related official IRS publications.
