Probate Administration in Illinois: The Step-by-Step Process

Probate administration in Illinois follows a defined sequence, and families who know the sequence make fewer expensive mistakes. This guide walks through the process the way it actually runs in DuPage County: what gets filed where, who has authority to act, and which deadlines are unforgiving. Where the Illinois Probate Act sets a specific rule, we cite the section so you can read it yourself.

First, Confirm the Estate Actually Needs Probate

Before anyone files anything, run this three-question test:

• Is there Illinois real estate titled in the decedent's name alone? If yes, you almost certainly need probate. Real estate cannot pass by small estate affidavit.
• Is the personal property under $150,000? For deaths on or after August 15, 2025, personal property up to $150,000, excluding vehicles registered with the Secretary of State, can pass by small estate affidavit instead of probate (755 ILCS 5/25-1).
• Was everything jointly owned or beneficiary-designated? Accounts with payable-on-death designations, jointly held property, and funded trusts pass outside probate no matter their value.

If the estate clears all three, read our guide to the small estate affidavit in Illinois before opening a case you may not need.

Step 1: File the Will With the Circuit Clerk Within 30 Days

Whoever holds the original will has a legal duty to file it with the Clerk of the Circuit Court in the county where the decedent lived within 30 days of learning of the death (755 ILCS 5/6-1). It applies even if the family plans no probate case. For a Villa Park, Lombard, or Wheaton decedent, that means the DuPage County Circuit Court Clerk.

Do these three things in week one:

• Locate the original will, not a copy: home safe, safe deposit box, the drafting attorney's office.
• Order certified copies of the death certificate. Banks, the court, and title companies will each want one.
• Make a rough asset list: real estate, bank and brokerage accounts, vehicles, business interests, and anything titled in the decedent's sole name.

Step 2: Petition for Probate at the DuPage Judicial Center

The probate case is filed in the county where the decedent resided (755 ILCS 5/5-1). For DuPage County, that is the Circuit Court of the 18th Judicial Circuit, Probate Division, at the DuPage Judicial Center, 505 N. County Farm Road, Wheaton. Illinois requires electronic filing in civil cases, so the petition goes in through the statewide e-filing system rather than a paper drop-off.

The petition asks the court to admit the will (if there is one) and to appoint a representative: an executor named in the will, or an administrator when there is no will. Illinois sets a priority order for who may serve as administrator, starting with the surviving spouse (755 ILCS 5/9-3).

Step 3: Letters of Office, Notice, and the Creditor Clock

Once the court admits the will and appoints the representative, the clerk issues letters of office, the document banks and title companies actually honor. Until letters issue, nobody has authority to move estate assets.

Three notice obligations start immediately:

• Heirs and legatees must be notified of the case and of their right to challenge the will's admission.
• Known creditors get direct notice.
• Unknown creditors are covered by publication, which starts a six-month claims window (755 ILCS 5/18-3).

That six-month window is why no Illinois probate estate closes in ninety days. For how the claims period interacts with the overall schedule, see our month-by-month breakdown of the Illinois probate timeline.

The Whole Process at a Glance

Independent or Supervised: Pick the Right Track Early

Illinois lets most estates run under independent administration (755 ILCS 5, Article XXVIII), where the representative acts without asking the judge's permission for each sale or payment. Supervised administration puts every significant act in front of the court. Independent is faster and cheaper; supervised exists for estates with conflict, distrust among heirs, or complicated assets. If family tension is already visible, raise the question with counsel before filing; the track you choose shapes every later step.

Pay People in the Right Order, Not the Loudest First

A representative who pays whoever calls most often creates personal liability. Illinois ranks claims in classes, and higher classes are paid in full before lower ones see anything: funeral and administration expenses come first, then the statutory awards, then debts and remaining claims (755 ILCS 5/18-10). Two practical rules:

• Pay nothing beyond funeral and obvious administration costs until the claims window closes and the full picture is known.
• Document the surviving spouse's and dependent children's statutory awards before distributing to anyone; these awards outrank most creditors and are routinely missed (755 ILCS 5/15-1).

If you are the executor, our companion guide to the executor's duties, deadlines, and pay in Illinois covers the role itself: duties, pay, and where personal liability hides.

Closing the Estate: The Final Checklist

An Illinois estate closes on paperwork, not on a feeling that the work is done. Before asking the court for discharge, confirm:

• The claims window has expired and every filed claim is paid, settled, or formally disallowed.
• Final income tax returns are filed and any Illinois estate tax question answered in writing.
• Real estate sales are closed and recorded with the DuPage County Recorder.
• The final account (or receipts and waivers under independent administration) is complete and signed.
• Distributions match the will or the intestacy statute exactly, with receipts from every beneficiary.

Only then does the court grant discharge, ending the representative's personal responsibility. What it all costs, and which costs are avoidable, is answered honestly in our guide to what probate costs in Illinois.

Sources: 755 ILCS 5/6-1 · 755 ILCS 5/5-1 · 755 ILCS 5/9-3 · 755 ILCS 5/14-1 · 755 ILCS 5/15-1 · 755 ILCS 5/18-3 · 755 ILCS 5/18-10 · 755 ILCS 5/25-1 · Illinois Legal Aid Online: probate · DuPage County Circuit Clerk · Illinois Courts e-filing