As a prospective adoptive parent in the process of adopting a U.S. citizen or resident, you'll need a taxpayer identifying number (TIN) for the child who is being adopted to claim the child as a dependent. If you don't have and are unable to obtain the child's Social Security number (SSN), you should request an adoption taxpayer identification number (ATIN) or individual taxpayer identification number (ITIN).

• An ATIN is available if a child who is a U.S. citizen or resident is lawfully placed in your household for legal adoption. To obtain an ATIN, use Form W-7A, Application for Taxpayer Identification Number for Pending U.S. Adoptions. For more information, refer to the Instructions for Form W-7A PDF and to Adoption taxpayer identification number.
• If the child isn't a U.S. citizen or resident, and if the child qualifies as a dependent, a TIN is still required. To obtain an ITIN, use Form W-7, Application for IRS Individual Taxpayer Identification Number. For more information, refer to Individual taxpayer identification number.

Please note that for tax years 2018 through 2025, you may not claim the child tax credit on either your original or an amended return if your child doesn't have an SSN valid for employment before the due date of your return (including extensions). If your child has an ATIN or an ITIN, your child may qualify you for the credit for other dependents.