How do I get my return approved if my daughter accidentally marked that nobody could claim her as a dependent?

Your remedy is to file your return that claims your daughter as a dependent by mailing your tax return.  You will not be able to e-file this year, even if her return has been amended.   You will need to print, sign and date your return in ink, and mail it.  If if is a joint return, both spouses must sign.

This is a very common problem that occurs when teenagers or young adults prepare first tax returns and do not realize that they are supposed to mark that they can be claimed as dependents.  That mistake blocks parents from e-filing due to the duplicate use of the child's SSN.

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.