Waiting for your child's amended return to be processed was futile. You will not be able to e-file your return this year with the duplicate use of their SSN. Your own return that claims him must be printed, signed and mailed.
Some users have had success by doing this:
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.**
