The Child Tax Credit starts when you file your tax return for the year your child was born

The Child Tax Credit is a reduction in the federal income tax you owe, not a payment you receive upfront. You claim it on your tax return — either Form 1040 or Form 1040-SR — for the tax year in which your child was born or adopted. The credit applies to children under age 17 at the end of that tax year.

If you file your 2024 tax return in early 2025, you would claim the credit for any child born or adopted during 2024. The credit reduces your tax bill dollar-for-dollar. If the credit is larger than the tax you owe, you may receive the difference as a refund, depending on which version of the credit you claim and your income.

The amount of the credit and the rules for receiving it have changed in recent years. The current credit is $2,000 per child under 17, though Congress has modified this amount before and may do so again. Check the IRS website or a tax professional for the exact amount for the year you are filing.

Key Takeaways

  • You claim the Child Tax Credit on your federal tax return for the year your child was born or adopted, not in a separate application process.
  • The credit currently reduces your tax bill by $2,000 per child under age 17, though this amount has changed in the past and may change again.
  • If the credit is larger than your tax bill, you may receive a refund, but the rules for refundable portions depend on your income and filing status.
  • You need your child's Social Security number and proof of relationship (usually a birth certificate) to claim the credit on your return.
  • The IRS allows you to claim the credit retroactively if you did not claim it in a prior year, though you must file an amended return.

How the credit reduces your tax bill

When you file your tax return, you calculate the federal income tax you owe based on your income and filing status. The Child Tax Credit then subtracts directly from that amount. If you owe $3,000 in tax and you have one child under 17, the $2,000 credit reduces your bill to $1,000.

If the credit is larger than your tax bill — for example, you owe $1,500 but have two children, making your credit $4,000 — the excess may be refunded to you. However, the refundable portion is limited. Currently, up to $1,700 per child can be refunded if you meet income thresholds, though this limit has changed before. Your tax software or a tax preparer can calculate the exact refundable amount based on your situation.

Income limits and phase-out rules

The full $2,000 credit is available if your modified adjusted gross income (MAGI) is below certain thresholds. For 2024, the threshold is $400,000 for married couples filing jointly and $200,000 for single filers and heads of household. If your income exceeds these amounts, the credit begins to reduce by $50 for each $1,000 (or fraction thereof) over the limit.

The refundable portion of the credit has its own income floor. You must have at least $2,500 in earned income to claim any refundable portion. If your earned income is below that, you can still claim the non-refundable credit to reduce your tax bill, but you will not receive a refund if the credit exceeds your tax.

What documents you need to claim the credit

To claim the Child Tax Credit, you need your child's full legal name and Social Security number. You will enter this information on Schedule 8812 (if claiming the refundable portion) or directly on your Form 1040, depending on your tax software or preparer's process.

You do not need to submit a birth certificate or adoption papers with your return, but the IRS can request them if they verify your claim. Keep these documents with your tax records for at least three years. If you do not have a Social Security number for your child, you cannot claim the credit until you obtain one.

Claiming the credit if you missed prior years

If you did not claim the Child Tax Credit in a year when you were may have access to to it, you can file an amended return using Form 1040-X. You have generally three years from the original due date of the return to amend and claim the credit. For example, if you did not claim the credit on your 2021 return, you can amend through April 15, 2024.

Filing an amended return takes longer than a regular return — typically four to six months for the IRS to process it. You can file the amendment yourself using tax software, through a tax preparer, or by mailing the form to the IRS. If amending results in a refund, the IRS will mail it to you or deposit it to your bank account if you provided direct deposit information.

How the credit differs from child support payments

The Child Tax Credit is a federal tax benefit and is separate from child support obligations or payments. Receiving the credit does not affect your child support case, and paying child support does not reduce the credit you can claim. Both the parent who has custody and the parent who pays support may have questions about who claims the credit — this is typically determined by your custody agreement or court order, not by the tax law itself.

If you are unsure whether you or the other parent should claim the credit, check your custody agreement or child support order. If the order does not specify, the parent with primary custody usually claims it, but you may need to contact your local child support enforcement office or a family law attorney for clarification in your specific situation.

Frequently Asked Questions

Can I claim the credit if I do not have a Social Security number for my child?

No. Your child must have a valid Social Security number to claim the credit. If your child was born in the United States and you have not yet obtained a number, you can apply through the Social Security Administration. If your child was born outside the United States, you will need to follow the process for obtaining a number for a non-citizen child.

What if my income is above the phase-out threshold?

The credit reduces by $50 for every $1,000 of income above the threshold. If your income is $50,000 above the threshold, your credit would reduce by $2,500. You may still receive a partial credit if the reduction does not eliminate it entirely. Use IRS worksheets or tax software to calculate your exact credit.

Do I have to claim the credit, or can I skip it?

You do not have to claim it, but there is no financial reason not to. Claiming the credit reduces your tax bill or increases your refund. The only reason to skip it would be if your custody agreement specifies that the other parent claims it, or if claiming it would affect your may be able to access for a means-tested benefit — a rare situation worth discussing with a tax professional.

Can both parents claim the same child?

No. Only one person can claim the credit for each child in a given year. If both parents try to claim the same child, the IRS will reject one of the returns or ask for clarification. Your custody agreement or court order should specify who claims the credit to avoid this conflict.