@johnashby382020 If you claimed a dependent that you should not have claimed, then AFTER your return has been fully processed you will need to amend to remove the dependent from your return. You cannot amend yet---the Form 1040X will not be available until late February. If you receive child-related refundable credits you will have to repay them.
Meanwhile, the return of the other parent or grandparents who can claim the child will be rejected when they try to e-file because of the duplicate use of the child's SSN. So....you need to alert them now. They can either seek IP PIN's to help them e-file or they can file their return by mail instead of e-filing.
GET IP pin in order to e-file if your dependent’s SSN was claimed on another return
https://www.irs.gov/newsroom/irs-takes-steps-to-help-prevent-refund-delays-by-accepting-duplicate-de...
https://www.irs.gov/identity-theft-fraud-scams/get-an-identity-protection-pin
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
