The general rule is that whichever parent the child resided with for the majority of the year (over 6 months) has the right to claim that child as a dependant for tax purposes. However, your ex can also claim her, and if he does, this will trigger an investigation by the IRS as to who actually has the right to claim the child.
I left my abusive husband on June 1st, 2006. I have had physical custody of my child since. He didn’t start paying child support until September. Today I finally got permanent custody. He is on long term disability and only pays taxes on his pension. I am a contract non-employee (1099) and must pay all taxes and social security by April 15th. Since I have had physical custody (he is currently only allowed to see her with a licensed mental health therapist) am I allowed to claim her as a dependent for 2006? I know I can claim her in 2007 but what about 2006? We are still married even though he cannot contact me until April 2008 without going to prison. So, the real question is: Can I claim my 10 year old daughter as a dependent for 2007 or do I need to talk to a tax person?