What should I do if my tax returns are being rejected because someone else has used my social security number.

You have to print, sign and mail your tax return.  

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 UPS or certified mail so you will know the IRS received the return.

If someone you know claimed you as a dependent and should not have done so, then they need to amend.