@dlux,
dlux wrote:
So I found out yesterday that my ex-husband claimed all 3 of our kids even though he's only supposed to claim 1. He even claimed my 20 year old that is out on her own and already did her taxes. Does anyone know what I have to do?
Is it that you want to report him? How did you find out? If you have legal rights to claim your kids on your tax form and you filled everything according to how you were legally supposed to - then no worries. Keep copies of everything that proves this fact.
If for some reason you want to report him - then use Form 3949-A you can get this from the IRS website and follow the instructions where to mail the form.