Filing for sole custody in Illinois is a significant legal process that requires careful preparation and understanding of state laws. If you seek sole custody—meaning you want to be the only one with decision-making authority and primary parenting time—you must demonstrate that this arrangement is in the best interest of the child. Below is a step-by-step guide on how to file for sole custody in Illinois.
Understanding Sole Custody in Illinois
In Illinois, child custody is referred to as the “allocation of parental responsibilities.” The term “sole custody” is not used in legal proceedings the way it was used in the past. Instead, courts allocate decision-making responsibilities and parenting time based on the child’s best interests. If you are seeking sole custody, that means you are requesting sole decision-making authority and primary parenting time, which will significantly limit the other parent’s role in the child’s upbringing.
If you already have a custody order, then you can petition the court to change the agreement by showing there have been significant changes in circumstances for you or your spouse. If you do not already have a custody order, then you will have to draft a Petition for Allocation of Parental Responsibilities to request the court for a custody order. Your attorney can help you draft these documents or you can find helpful forms on your local county courthouse’s webstite.
There are many reasons a parent may seek primary custody or “sole” custody, but the most common reason is that the other parent is unfit for their parenting duties. A parent can be determined unfit if they pose a danger to the child, a danger to themselves, or if they have some sort of substance abuse problem. Keep reading to learn more, and also check out our article titled “Can You Lose Custody for Child Endangerment in Illinois?”
Sole Decision-Making Authority
If sole decision making authority is granted, one parent will have the exclusive right to make major decisions regarding the child’s upbringing, including their:
- Education
- Healthcare
- Religious upbringing
- Extracurricular activities
Primary Parenting Time
The parent with the most parenting time is typically called the custodial parent. The child primarily lives with the custodial parent, while the non-custodial parent may have limited parenting time or visitation rights which can be supervised if necessary. Courts generally believe that it is in the child’s best interest to have both parents involved in their life. Courts will only limit a parent to supervised visits if there is an egregious reason to do so.
Steps to File for Sole Custody in Illinois
1. Determine Grounds for Sole Custody
For a court to award primary parenting time and sole decision making authority to one parent, there need to be very good reasons for doing so. To obtain sole custody, you must prove that it is in the child’s best interest, and that the other parent is truly unfit to parent. Courts may grant sole custody if:
- The other parent has a history of abuse or neglect.
- The other parent has some sort of substance abuse or mental health issue that is affecting their ability to care for their child.
- The other parent is absent, unwilling to participate in the child’s life, or voluntarily relinquishes their parental rights.
- The parents have a high level of conflict that makes joint decision-making impossible.
- The child’s safety or well-being is at risk with the other parent for any other reason that can be articulated.
2. File a Petition for Allocation of Parental Responsibilities
The process for filing your petition can be slightly different if you already have a custody agreement in place, but the process is largely the same. To start the process, you must file a Petition for Allocation of Parental Responsibilities with the family court in the county where the child resides (or file a Petition to Modify the Allocation of Parental Responsibilities if you already have a custody order in place). This petition should include the following:
- Your request for sole decision-making authority and primary parenting time.
- A statement explaining why sole custody is in the child’s best interest.
- Any supporting evidence, such as police reports, medical records, or witness statements.
When you are done drafting your petition it must be filed. Filing can be done in person at the courthouse or online through their e-filing portal. Talk to your attorney or call your local county courthouse for more information about filing in your county. After filing you will likely need to set a court date, if one is not already set, and send a notice of the hearing to your spouse with a copy of your petition.
3. Serve the Other Parent
The other parent must be formally notified of the custody proceedings to modify an existing order or create a new one. Service is typically done through a process server, sheriff, or certified mail if the case is already underway, which ensures your spouse receives legal notice and has an opportunity to respond. You should check the rules in your county regarding service of your petition to avoid any unnecessary delays in your case.
Service can be difficult if your spouse is avoiding it. To learn more about the service process and its difficulties, check out our article titled “Can I Get a Divorce Without My Spouse Knowing?”
4. Attend Mediation (If Required)
Illinois courts often require parents to attend mediation to reach a custody agreement. Mediation involves a neutral third party mediator that works with both parties (and their attorneys) to reach a custom agreement. Mediation is often used in divorce but can also be used for resolving other conflicts. This approach can be very effective and save time/money if the parties are able to communicate effectively, which is why mediation is often required.
Mediation may, however, be waived in cases involving domestic violence or some other extreme conflict. You should notify the judge and your attorney about any incidents of domestic violence.
5. Prepare for the Court Hearing
If the parents cannot agree on custody arrangements in mediation, the case will go before a judge. To strengthen your case, you should:
- Gather evidence proving why sole custody is necessary (i.e. any evidence your spouse is unfit to parent such as evidence of substance abuse, physical abuse, or neglect, and evidence of your fitness to parent).
- Provide testimony from witnesses, such as teachers, doctors, or relatives about your fitness to parent or spouse’s unfitness to parent.
- Demonstrate your ability to provide a stable and nurturing environment for the child.
Presenting evidence in court can be difficult, but having well organized exhibits and a plan of action will go a long way. To learn more, check out our article titled “How to Present Evidence in Family Court in Illinois.”
6. Attend the Custody Hearing
During the hearing, both parents will present their arguments, and the judge will consider several factors, including:
- The child’s relationship with each parent.
- The age/maturity of the child
- The child’s adjustment to their home, school, and community.
- The mental and physical health of both parents.
- Any history of abuse, neglect, or substance abuse.
- Each parent’s willingness to facilitate a relationship between the child and the other parent.
Multiple hearings may be necessary depending on the amount of evidence or number of issues in the case. Be prepared for several long days in court with multiple hearings.
7. Receive the Court’s Decision
The judge will issue a final ruling based on the evidence and testimony presented during the custody hearings. If sole custody is granted, the decision will be formalized in a Parenting Plan outlining parental responsibilities, decision-making authority, and parenting time.
Modifying a Custody Order
If there are significant changes in you or your spouse’s circumstances, either parent can request a modification of the custody order by demonstrating that significant change, and how it affects the child’s well-being. An example of a significant change could be getting a new job where you make significantly more, or less, than you made at your last job.
Seek Legal Assistance
Child custody cases can be complex and emotionally charged. Gathering all the evidence and keeping it straight can be difficult on your own, especially when you have to argue in front of the judge. Consulting an experienced family law attorney can help you build a strong case, protect your parental rights, and ensure the best outcome for you and your child.
Conclusion: How to File for Sole Custody in Illinois
Filing for sole custody in Illinois requires proving that it is in the child’s best interest. By understanding the legal process, gathering strong evidence, and seeking professional legal guidance, you can effectively navigate the court system and advocate for the custody arrangement that best supports your child’s well-being.
MEET WITH AN ILLINOIS FAMILY LAW ATTORNEY TODAY
The Family Law attorneys at Koth Gregory & Nieminski understand that your family is the top priority, which is why we offer SAME-DAY APPOINTMENTS. If you need a divorce or other family law services, you can schedule your first meeting through our online appointment calendar. We look forward to meeting you.
Disclaimer: This article (How to File for Sole Custody in Illinois) may contain information that is outdated as Illinois law continuously evolves. Meeting with an experienced family law attorney is the best way to ensure you are receiving the most current information about How to File for Sole Custody in Illinois.
Published by Dustin Koth on March 5, 2025
