The correct claiming of the child will be determined by the court document.
If the custodial parent claims the child in error, the noncustodial parent should file their return correctly even if they know the child has already been claimed. Attach a copy of the court decree to the return to avoid delay in receiving a refund.
I always recommend that court documents indicate which year each parent will be eligible for the child's exemption. Example: mother claims even years/ father claims odd years, etc
Master Tax Advisor, Enrolled Agent
I am a Master Tax Advisor and Enrolled Agent. I have 40 years experience. Trucking specialist.