<prompt> Human: TL;DR Someone has fraudulently claimed my son as a dependent and I need information on whether I have taken the right action andor what I need to do. Background: My son and I have lived with my mother his grandmother for the entirety of his life. His mother left us when he was two months old, and I was unable to care for him independently and therefore we have been her dependents for every year since that point. She always has claimed both of us, and this year, I was successfully able to finish college and get a job in my profession. However, she still made more than me and did provide more than 50 of both of our care through tax season 2014. I filed separately and individually, but I did not claim my son because she was going to claim him. Situation: When my mother was filing her taxes, the claim was denied because my sons information was already claimed on someone elses taxes. As far as I know, no one else should have my sons SSN. And there is absolutely no one else that I would allow to claim him. Our Action: We printed out my moms tax return and included his social security card, birth certificate, medical bills from last year, proof of medical coverage with address listed, a letter from his school stating verifying residence, a copy of my mothers 2013 return showing both of us as dependents, my own social and state ID, a bill showing my residence here, a picture of my son and myself at his school AND at our household, a letter notarized from a friend stating that my son lives with me under this household, and I think thats it...Definitely overkill, but we are freaking out!! Suspects: My ex, who is the non-custodial parent and has never even paid child support, or my father, who has the same name as us He is Jr., we are 3rd and 4th, but not sure what his motivation would be? Can someone please let me know what other action I take from here? What else should I do? Am I doing the right thing? We havent sent off our documents yet but will do so later today...  <response>: Your action will be to mail grandmothers return in, rather than filing it electronically. The IRS will follow up with both people who claim the same SSN as a dependent, and the one who is in error has to file an amended return. Since you have the proofs, you will win this.See next steps on this page: It mentions a Form 14039. Your situation is a little different in that the SSN being used is not the taxpayers but the dependents. So maybe you need to wait to hear from the IRS instead. 