If you made a mistake and claimed a child when you should not have done so, alert the other parent asap. When they try to e-file their return claiming the child, their e-file is going to be rejected. They will have two choices----one would be to print, sign and mail their return that claims the child. They do not have to wait for you to amend. Waiting will not help them at all.
The other possibility for them is to get IP PIN's and try to e-file:
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
Whichever remedy the other parent chooses, they have no reason to wait for you to amend. Your amended return will take months to be processed. And...you can expect to pay back child-related credits that you receive for claiming the child.
**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.**
