CP08: You May Qualify for the Additional Child Tax Credit

Why you might get this

• The IRS reviewed your tax return and believes you may be eligible for the Additional Child Tax Credit (a refundable credit for people who didn't get the full Child Tax Credit).
• You may have a qualifying child that could earn you a refund you didn't already claim.
• Note: The IRS says some CP08 notices were sent by mistake. Check the tax year listed on your notice and the special instructions before you respond.

The deadline

The notice asks you to send back your completed forms by the date printed on your CP08. This is a chance to claim a refund you may be owed, not a bill you have to pay. Check the exact date on your own notice.

This notice doesn't carry a fixed response deadline, but it still deserves attention — see what to do below.

What to do

1. Read your CP08 notice carefully and check the tax year it covers.
2. For tax year 2025: confirm each qualifying child has a valid-for-work Social Security number issued before your return's due date. If they don't, you aren't eligible and don't need to respond.
3. Fill out Form 15110, the Additional Child Tax Credit Worksheet.
4. If the worksheet shows you have at least one qualifying child, also complete Schedule 8812, Credits for Qualifying Children and Other Dependents.
5. Send both completed forms back to the IRS, either by mail using the envelope provided or online through the Documentation Upload Tool with the access code on your notice.
6. If you mail it and lost the envelope, use the address in the top left corner of your notice.

What happens if you ignore it

If you skip it, you may simply miss out on a refund you could be owed — this notice is not a bill. If you do qualify and respond, you should get your refund in about 8 to 10 weeks (if you owe nothing else). If you don't hear back in that time, you can call the IRS at 800-829-1954 to check.

If the IRS denies your credit, it will send a letter explaining why. If you need help, you can get free assistance from the Taxpayer Advocate Service or a Low Income Taxpayer Clinic, or authorize someone to represent you before the IRS.

A CP08 notice is actually good news most of the time: the IRS believes you may qualify for the Additional Child Tax Credit (ACTC) — a refundable credit that can put money back in your pocket if you didn't get the full Child Tax Credit. In other words, they think you might be owed a refund.

To claim it, read your notice carefully and check the tax year it covers. Then fill out Form 15110, the Additional Child Tax Credit Worksheet. If that worksheet shows you have at least one qualifying child, also complete Schedule 8812. Send both forms back by the date printed on your notice, either in the envelope provided or online through the Documentation Upload Tool using the access code on your letter.

Heads up: the IRS says a batch of CP08 notices went out by mistake, and the rules changed for tax year 2025 around Social Security numbers. Double-check the special instructions for your tax year before responding — if you don't meet the SSN rule, you don't need to reply.

If you qualify and respond, refunds usually arrive in 8 to 10 weeks. Solace can keep an eye on your IRS account so you know when things move.