The IRS code dictates which parent is allowed to claim a minor child as a dependent and receive the tax dependency exemption.
Only one parent may claim his or her child as a dependent. Typically IRS considers a child of a divorced parent as the “qualifying child” of the custodial parent. There are certain instances when the child will be treated as the qualifying child of the noncustodial parent.
For example, the custodial parent may use either IRS Form 8332 or a similar statement (containing the same information required by the form) to make the written declaration to release the exemption to the noncustodial parent. The noncustodial parent must attach a copy of the form or statement to his or her tax return. 
The exemption can be released for one year, for a number of specified years (such as alternate years), or for all future years, as specified in the declaration.
Where both parents are eligible to claim the child as a qualifying dependent, such as when the child has lived with each parent an equal amount of time, then it is the parent with the greater adjusted gross income (AGI) who claims the child as a dependent for tax purposes.
Although Florida no longer uses the terms “custodial parent” or “noncustodial parent”, the Internal Revenue Code does use these terms and therefore this article also makes mention of these terms for the ease of reference.
It is important to keep in mind that IRS generally considers the number of nights the child resides with each parent during a given year and not the number of days. Consequently, it is the parent who has custody of the child for the greater number of nights in a given year that gets the dependency exemption.
Your final judgment of dissolution of marriage and/or the parenting plan would usually address this issue. As the dependency exemption is often used by the divorcing parents as a bargaining chip in divorce negotiations, the dependency exemption is almost always addressed in a divorce decree.
Quite often the divorcing parents alternate claiming their child or if the parents have multiple children, the court may award the dependency exemption for all the children to the custodial parent. Where there is an even number of children, the court may award the exemption for half of the children to the custodial parent and the remaining half of the exemptions to the noncustodial parent. The court may also award the exemption for the younger children to the custodial parent so that the parent can then claim the exemption for a longer period of time. In essence, in Florida the courts are governed by the best interests of the child standard.
However, you should be aware that since the federal law supersedes state law, for the noncustodial parent to claim his or her child as a dependent that noncustodial parent must include a signed IRS Form 8332 with the tax return documenting the custodial parent’s written consent and thereby ensuring that the IRS will accept the dependency deduction.
Now, the custodial parent may revoke the release of the dependency exemption at any time. The custodial parent may revoke the release through the same IRS Form 8332. The revocation becomes effective during the tax year following the year in which the custodial parent revoked the initial release of claim to exemption. That revocation can be for specific future years or all future years.
For example, if in 2009 the custodial parent releases his or her claim to the exemption on the IRS Form 8332 for the years 2010 through 2013 and then in 2011 decides to revoke this previous release of the exemption, this revocation will only be effective for 2012 and 2013 provided that the custodial parent has furnished a copy of his or her revocation to the noncustodial parent in 2011, the year of the revocation.
Going through a divorce is no easy task. It is an emotionally and financially strenuous time for everyone involved and that stress is often magnified when minor children are involved. There is no simple divorce. Each divorce proceeding is unique with its own procedural requirements. However, there is one matter that should be addressed by all parties to a divorce proceeding, especially when minor children are involved, and that is the tax implications of a divorce.
One of the tax implications divorcing couples with minor children should keep in mind is, of course, the exemption for dependent children that we have discussed in this article. Apart from the dependency exemption, there are tax implications in spousal support, child support, in the change in the filing status, in the mortgage interest deduction, which usually is addressed when equitable distribution is discussed. Consequently, it would be prudent to consult with a tax professional in addition to your divorce attorney in order to ensure that you are in fact getting the best deal for yourself under the circumstances.
 For post-1984 and pre-2009 divorce decrees or agreements, the noncustodial parent can attach certain pages from the divorce decree or agreement instead of Form 8332, provided that these pages are substantially similar to Form 8332. If the divorce decree or agreement was executed after 2008, the noncustodial parent can no longer attach certain pages from a divorce decree or agreement instead of Form 8332. See IRS Form 8332 (Rev. 1-2010).