Custodial parent releases claim on Form 8332
For tax filing purposes, having custody is not necessarily the same as it is for a divorce decree. While a divorce decree can state that one parent has custody of a child, the requirement for the IRS generally depends on which parent the child lived with for the greater number of nights.
If you have custody of your child, but want to release the right to claim your child's exemption to the noncustodial parent you’ll need to fill out Form 8332. All that’s needed is your child's name, the tax year, your Social Security number, then your signature and date. If you prefer to release your claim to your child's exemption for more than one tax year, enter the same information in part two rather than part one. Once complete, give the form to your child's noncustodial parent, not the IRS. They will file it with their tax return. If you release your claim for multiple tax years, you only need to fill out the form once: the other parent will attach copies of the original to their return each year.