That means that the IRS has already received a tax return for the same SSN and will not allow another e-file with the same SSN.
If you or a dependent that you are entitled to claim has already been claimed by another taxpayer, your e-filed return will reject since the SSN has already been used (either intentionally or in error such as a mistyped SSN).
Your only recourse is to file a correct tax return, claiming what you are entitled to claim, then print and mail the return.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
