Divorce Process in Illinois: Filing, Property, and Prove-Up

The divorce process in Illinois begins with a 90-day residency requirement and ends when a judge signs a Judgment of Dissolution of Marriage. In between, you file a petition citing irreconcilable differences, serve your spouse, exchange financial information, and either settle or try the case. Illinois is a no-fault state, so no one has to prove wrongdoing. Uncontested cases can finish in a few months. Contested ones sometimes take more than a year.

Who Can File and On What Grounds

At least one spouse must have lived in Illinois for 90 consecutive days before the petition is filed or before the judgment is entered.¹ Time stationed in Illinois as an active-duty service member counts. You file in the circuit court of the county where either spouse lives.

Illinois recognizes only one ground: irreconcilable differences. If you and your spouse have lived separate and apart for at least six continuous months before the judgment is entered, that period is conclusive proof of irreconcilable differences, and the other spouse cannot contest it.² Living “separate and apart” can include remaining in the same house if the marital relationship has genuinely ended.

The Simplified Track for Short, Simple Marriages

Before starting a standard case, check whether you qualify for joint simplified dissolution. This streamlined process skips most discovery and formal service, but every one of these conditions must be met when you file:³

No children were born or adopted during the marriage, and the wife is not pregnant.
The marriage lasted eight years or less.
Total marital property, after subtracting debts, is worth less than $50,000, with no interest in real estate or retirement benefits (other than IRAs with a combined value under $10,000).
Combined gross annual income is under $60,000, and neither spouse earns more than $30,000 individually.
Neither spouse seeks maintenance.
You already have a written agreement dividing every asset worth more than $100 and allocating debts.

Miss even one threshold, and you use the standard process described below.

Filing the Petition

The core document is the Petition for Dissolution of Marriage. If you have children under 18, use the “Divorce with Children” version instead.⁴ You’ll also need a Summons. Standardized forms are available through the Illinois Courts website.⁵

Both spouses must complete a Financial Affidavit, a Supreme Court-approved form required in every circuit court.⁶ It covers all income, monthly expenses, assets, and debts, and requires supporting documents like pay stubs, tax returns with schedules, and bank statements. When children are involved, supplemental forms on child support and health insurance apply.⁷ Filing inaccurate or misleading information intentionally or recklessly can trigger sanctions, including paying the other side’s attorney fees.

Illinois requires all civil filings to go through eFileIL, the statewide electronic filing system, using an approved provider.⁸ Paper walk-ins aren’t accepted. Filing fees vary by county and typically run into the several hundreds. If you can’t afford the fee, submit an Application for Waiver of Court Fees through the same system.⁹

Serving Your Spouse

After the court accepts your filing, your spouse must be formally served. You have several options:

Pay the county sheriff to hand-deliver the documents. Fees are usually under $100, sometimes with mileage added.
Hire a licensed private process server, which helps when the sheriff’s office has limited hours or your spouse is hard to reach.
Have a cooperative spouse sign an Entry of Appearance, which eliminates the need for formal service.

If your spouse cannot be located after a genuine search, Illinois allows service by publication. You file an affidavit describing your diligent inquiry, and notice runs in a newspaper in the county where the case is pending. Within 10 days of the first publication, the clerk mails a copy to the last known address.¹⁰ Courts scrutinize whether you truly exhausted other methods first.

Getting Temporary Orders While the Case Is Pending

Divorce cases take months, and life doesn’t pause. Under 750 ILCS 5/501, you can ask the court for temporary relief while the case is pending. The court decides these motions on a summary basis, relying mainly on the financial affidavits and supporting documents.¹¹ Available relief includes:

Temporary maintenance or child support so no one goes without basic support during litigation.
Restraining orders preventing either spouse from transferring, hiding, or disposing of property outside the ordinary course of daily life.
Orders prohibiting a parent from removing a child from the court’s jurisdiction for more than 14 days.
Orders barring a spouse from striking or interfering with the personal liberty of the other spouse or any child.

A judge can also award interim attorney fees, weighing each party’s income, assets, earning capacity, and case complexity. Interim awards don’t lock in who ultimately pays; the final judgment can reallocate them.¹¹

Dividing Property and Debts

Illinois is an equitable distribution state. The court divides marital property fairly, which is not necessarily 50/50. First it separates marital from non-marital property. Marital property covers almost everything either spouse acquired during the marriage, including debts. Non-marital property is set aside and returned to its owner.¹² Non-marital categories include:

Property owned before the marriage
Gifts or inheritances received by one spouse, even during the marriage
Property excluded by a valid prenuptial or postnuptial agreement
Property acquired after a judgment of legal separation
The increase in value of non-marital property, subject to reimbursement rights for the other spouse’s contributions

The court then divides the marital estate based on statutory factors, including each spouse’s contribution to acquiring or preserving property (including homemaker contributions), each spouse’s economic circumstances, the length of the marriage, and any dissipation of assets.¹²

Retirement accounts often need their own court order. State pension systems require a Qualified Illinois Domestic Relations Order (QILDRO); private employer plans like 401(k)s use a federal Qualified Domestic Relations Order (QDRO). These orders direct plan administrators to pay a portion to the other spouse. Errors here can permanently cost retirement money.

Spousal Maintenance

Maintenance (alimony) is not automatic. A court first decides whether a spouse qualifies, then applies a statutory formula when the couple’s combined net annual income is $500,000 or less.¹³

The monthly payment equals 33.33% of the paying spouse’s net income minus 25% of the receiving spouse’s net income. The receiving spouse’s combined income after the payment cannot exceed 40% of the couple’s total net income.

Duration depends on how long the marriage lasted. The statute multiplies the marriage length by a percentage that grows with time:¹³

Under 5 years: 20%
5 to 6 years: 24%
6 to 7 years: 28%
7 to 8 years: 32%
8 to 9 years: 36%
9 to 10 years: 40%
10 to 15 years: 44% up to 60%, increasing annually
15 to 20 years: 64% up to 80%, increasing annually
20 years or more: the court may order maintenance equal to the length of the marriage or indefinitely

A 10-year marriage produces roughly 4.4 years of maintenance (10 × 0.44). When combined income exceeds $500,000, the court sets maintenance without the formula. Courts can also deviate when a spouse already pays support from a prior relationship.

Child Support and Parenting Decisions

Illinois uses an income shares model that estimates what both parents would have spent on the children together. The steps:¹⁴

Calculate each parent’s net income by starting with gross income and subtracting taxes and adjustments like maintenance paid.
Combine the net incomes and look up the basic support obligation on the schedule published by the Illinois Department of Healthcare and Family Services.
Split the obligation proportionally. A parent earning 60% of combined income owes 60% of the obligation.
Adjust for shared parenting when one parent has 146 or more overnight stays per year.
Divide childcare, health insurance premiums, and uninsured medical costs in proportion to income.

The calculated amount is presumed correct unless a court finds it inappropriate given factors like special medical needs, extraordinary educational expenses, or the family’s prior standard of living.¹⁴

Illinois no longer uses “custody” and “visitation.” Courts allocate parenting time (the schedule) and significant decision-making responsibilities (education, healthcare, religion). Everything turns on the best interests of the child, with the court weighing each parent’s wishes, the child’s wishes given maturity, each parent’s caregiving in the two years before filing, and each parent’s willingness to support the child’s relationship with the other parent.¹⁵

Parents must file a Parenting Plan covering decision-making allocation and the parenting time schedule. If parents can’t agree, the court orders mediation unless something like a history of domestic violence makes it inappropriate.¹⁶ An agreed plan, once approved, becomes a binding court order.

Settlement or Trial

Both sides exchange financial information through formal discovery, which goes further than the Financial Affidavit. Requests may cover credit card statements, property appraisals, and business valuations. Complex estates can require appraisers or forensic accountants and stretch discovery over months.

Most Illinois divorces settle. The settlement takes the form of a Marital Settlement Agreement (MSA), a detailed contract dividing bank accounts, real estate, retirement funds, and debts, and addressing maintenance. When children are involved, the Parenting Plan is filed alongside. Both become enforceable court orders once the judge approves them. Any issues that remain go to trial, where the judge hears evidence and applies the statutory factors. Because trials are expensive, even high-conflict cases often settle most issues and litigate only the true sticking points.

Prove-Up and Final Judgment

Once every issue is resolved, the case moves to a prove-up hearing. At this brief appearance the petitioner testifies to the basic facts: the marriage, residency, the breakdown of the relationship, and the settlement terms. The judge reviews the MSA and Parenting Plan for fairness and consistency with Illinois law.²

If satisfied, the judge signs a Judgment of Dissolution of Marriage, which ends the marriage. Either party then has 30 days to file a post-trial motion asking the court to reconsider or modify the ruling.¹⁷ Once that window passes, the judgment is final. The same 30-day deadline applies to a motion to vacate a default judgment, and the odds of overturning one drop sharply after that.

1
Illinois General Assembly. Illinois Code 750 ILCS 5/401 – Dissolution of Marriage
2
Illinois General Assembly. Illinois Code 750 ILCS 5 – Illinois Marriage and Dissolution of Marriage Act
3
Illinois General Assembly. Illinois Code 750 ILCS 5/452 – Joint Simplified Dissolution
4
Illinois Courts. Petition for Divorce – Divorce No Children Under 18
5
Office of the Illinois Courts. Divorce, Child Support, and Maintenance
6
Illinois Courts. Financial Affidavit – Family and Divorce
7
Office of the Illinois Courts. Financial Affidavit
8
Office of the Illinois Courts. Circuit Court E-Filing
9
Office of the Illinois Courts. Supreme Court Fee Waiver
10
Illinois General Assembly. Illinois Code 735 ILCS 5/2-206 – Service by Publication
11
Illinois General Assembly. Illinois Code 750 ILCS 5/501 – Temporary Relief
12
Illinois General Assembly. Illinois Code 750 ILCS 5/503 – Disposition of Property and Debts
13
Illinois General Assembly. Illinois Code 750 ILCS 5/504 – Maintenance
14
Illinois General Assembly. Illinois Code 750 ILCS 5/505 – Child Support
15
Illinois General Assembly. Illinois Code 750 ILCS 5/602.7 – Best Interests of Child
16
Illinois General Assembly. Illinois Code 750 ILCS 5/602.10 – Parenting Plan
17
Illinois General Assembly. Illinois Code 735 ILCS 5/2-1202 – Post-Trial Motions