My tax return was rejected because my dependent file her own tax return, She was my dependent until the end of September 2017. What do I do?

[DanielV01 · Accepted solution]

It depends.  First, in the IRS' eyes, there is no distinction between a part-year or a full-year dependent.  To the IRS, she either was or was not your dependent.  Please note this FAQ to ensure whether or not she was your dependent:  https://ttlc.intuit.com/replies/5187060.  (Please comment if your dependent married last year).

Assuming she is your dependent, you would advise her to amend her return because you intend to claim her.  Her amending the return will speed up processing, but you will still need to mail-in your return if you wish to claim her.  Another option is to e-file the return without her to receive that portion of the refund, and then amend the return to include her.

But you will not be able to claim her through an e-file.  Once an SSN has been used through electronic filing, it is not possible to be used again on another e-file, even if it was an error originally.  Her cooperation can speed up the process, but it will still take time for this to get fixed with the IRS.