my ex is trying to claim my daughter even though he owes me back pay, pays less that min wage child support (because he is disabled) and only recently started paying supports. Can he do this?
IF you divorce decree does not address this issue, then it would be up to the two of you to agree who gets to claim the child for tax exemption. There is a form that the IRS/or tax preparer should give to your ex at the time he tries to file. Without it, he can not claim the exemption.