You don't earn the right to claim your child as a dependent on your taxes simply because you pay child support – the Internal Revenue Service's rules are much more complicated than that. The amount of time your child lives with you is a big factor. If she doesn't live with you at all, you'll probably have to rely on your ex's goodwill if you want to claim the dependent deduction. The IRS doesn't let both parents claim their child in the same tax year.
Claiming a child on your income taxes typically requires meeting the IRS dependent rules and tiebreaker criteria. However, your ex also can choose to transfer the dependent deduction to you using IRS Form 8332.
Reviewing IRS Dependent Rules
Your child must meet IRS rules as a qualifying dependent before either you or your ex can claim her. A qualifying child must be younger than 19, or under 24 if she's a full-time college student. If she has any income, she can’t provide more than half of her own support. One major factor in determining whether your child is a qualifying child is whether she lived in your home for at least six months of the year.
Understanding Tiebreaker Rules
Divorce creates a new wrinkle in IRS rules, and federal law has established tiebreaker criteria to determine which parent can claim a child when parents no longer live together. If you and your ex both want to claim the exemption, it goes to the parent with whom the child lived most during the tax year. If your child didn't live with you at all, or if you only had visitation or parenting time with her on weekends, you're probably out of luck.
Even if she spent every Friday and Saturday night with you, this only adds up to about 104 days. She would have spent approximately 261 days with your ex, so your ex would get the dependent deduction.
Waiving the Exemption
The IRS defers to parents when they make their own arrangement regarding their child's dependent deduction. You're permitted to override IRS rules. If the IRS gives your ex the deduction and if she's willing to transfer it to you, she can sign IRS Form 8332 so you can submit it with your tax return. If you include this form, you can claim the dependent deduction for your child regardless of how long she did or didn't live with you.
Other Tax Considerations
You can't claim a dependent at all if you qualify as someone else's dependent. For example, if you're younger than 24, go to school full-time, and if you lived with your parents half the tax year and contributed less than half of your own support, you can't claim your child under any circumstances. Your parents have the right to claim you, and it doesn't matter whether they actually do or not. You also can't claim a dependent unless you earn sufficient income to file a tax return.