General Rule: One Child, One Claim
Only one person can claim a child as a qualifying child for tax benefits. Parents cannot split or share these benefits. To avoid processing delays, parents should agree on who will claim the child.
Custodial Parent Priority
Generally, the custodial parent, defined as the one with whom the child lives for most nights during the year, claims the child as a dependent. However, if the child lives with each parent for an equal number of nights, the parent with the higher adjusted gross income (AGI) is considered the custodial parent.
In most cases, because of the residency test, the custodial parent claims the child on their tax return.
Tie-Breaker Rules
Even if a child meets the qualifying criteria for both parents, only one can claim them. Refer to Publication 504, Divorced or Separated Individuals, for detailed eligibility information.
Noncustodial Parent Exception
A noncustodial parent can claim the child as a dependent if the custodial parent releases the dependency exemption. This requires a written declaration, typically Form 8332, Release/Revocation of Release of Claim to Exemption for Child by Custodial Parent, which the noncustodial parent must include with their tax return.
This release can apply to the child tax credit, additional child tax credit, and credit for other dependents, but not the earned income credit, dependent care credit, or head of household filing status.
For more information, consult Publication 501, Dependents, Standard Deduction, and Filing Information, and the IRS resource "Whom May I Claim as a Dependent?".