Since the social security numbers and names, first and last of your children were all correct, then it would have to be one of the following remaining options:
- One or more individual claimed as a qualifying dependent exceeds the age limit.
- The first and second stimulus affect children under 17 years old only.
- Your adjusted gross income is greater than the limits - the Recovery Rebate Credit will be phased out for amounts above
- $112,500 for head of household
- $150,000 for married filing jointly
- Some other calculation error - perhaps there is an amount they think was already received.
For more information, see: Recovery Rebate Credit Frequently Asked Questions | Internal Revenue Service
