the rejection is by the IRS not Turbotax. Your accountant friend is wrong. Once a tax return is filed with a dependent's tax ID number, the IRS will not accept another e-filed return with that same dependent even if the first return is amended to remove the dependent. So, if a parent tries to e-file a tax return claiming a child that has already been claimed for the year, the return will be rejected by the IRS. Your return will have to be paper-filed.
mail your return and use a tracking service.
https://turbotax.intuit.com/tax-tips/family/what-happens-when-both-parents-claim-a-child-on-a-tax-re...
