You will need your child's Social Security number to claim your child as a dependent on a tax return; apply for government benefit; obtain health insurance; buy savings bonds; or open a bank account for your child. If you have lost your child's Social Security card and need the number, you will need to apply for a new card through the Social Security Administration. Social Security numbers will not be released over the phone. It is best to replace it promptly so you have it when needed.
Complete a Social Security card application. The application can be obtained online on the Social Security Administration's website or in any Social Security Administration office. You can also request an application by calling (800) 772-1213 and having it mailed to your home.
Gather proof of your child's age and identity. You will need to provide two documents--one showing your child's age and one showing his identity. A birth certificate can be used to prove your child's age, but not identity, according to the Social Security Administration. To prove identity, the preferable document is a U.S. passport; other acceptable documents include hospital or doctor records, an adoption decree, a religious record or a school identification card. All documents must be originals or certified by the issuing agency. Copies and notarized documents will not be accepted.
Gather proof of your identity. Acceptable documents include a driver's license, a state-issued identification card or a U.S. passport, according to the Social Security Administration. Again, remember that you must provide original or certified documents to your local Social Security Administration office.
Visit your local Social Security office with the completed application and the necessary documents to prove your child's age and identity and your identity.