For people who share custody of a child (either divorced parents or parents who were never married), these special rules apply:
Tax obligations trump court orders. Even if the court ordered you to file in a certain way, IRS rules must be obeyed.
Both parents cannot claim the same child for tax purposes. One child, one dependent exemption.
The tax benefits from one qualifying child cannot be split among both parents.
The noncustodial parent (meaning they had the child for fewer than half of the nights during the tax year) can claim the qualifying child for the Child Tax Credit and the Dependent Exemption if:
The couple is divorced, legally separated, or lived apart for the last six months of the year
The parents provided for the child’s support
The child lived with one or both parents for most of the year
The custodial parent signs IRS form 8332, which states that they won’t claim the child as a dependent
Please note that Item 4 is the only exception to Item 3 – the noncustodial parent can claim the Child Tax Credit and/or the Dependent Exemption even though the custodial parent can claim the child for the Head of Household filing status and Earned Tax Credit.