If someone you loved recently passed away and left behind property, bank accounts, or other assets in Cook County, you're probably staring down the probate process and wondering where to even start. The paperwork is the foundation of everything. Without the right documents filed correctly, the court can't appoint you as executor, and you can't legally manage or distribute the estate. Getting the paperwork right the first time saves weeks or even months of delays, extra court appearances, and headaches.

This guide breaks down exactly what paperwork you need to open probate in Cook County, Illinois, in the order you'll need it.

What Does It Mean to "Open" Probate in Cook County?

Opening probate is the legal process of asking the Cook County Circuit Court's Probate Division to formally recognize a person's death and begin the court-supervised process of settling their estate. This means validating the will (if one exists), appointing a representative to manage the estate, paying debts, and distributing remaining assets to beneficiaries.

In Cook County, probate cases are filed at the Daley Center in downtown Chicago at 50 W. Washington Street, Room 1202. The Cook County Probate Division handles all probate matters for the county.

What Paperwork Do You Actually Need to Open Probate?

Here's a straightforward list of the documents you'll need to gather and file:

1. The Original Will (If One Exists)

If the deceased person had a will, you need the original signed document not a photocopy. Under Illinois law (755 ILCS 5/6-1), the person who has custody of the will is required to file it with the court within 30 days of learning about the death. If you can only find a copy, the court may still accept it, but you'll need to explain the circumstances, and the process gets more complicated.

2. A Certified Copy of the Death Certificate

The court requires a certified death certificate issued by the Cook County Clerk's office or the county where the person died. You'll want to request multiple certified copies at least 10 to 15 because banks, insurance companies, and other institutions will each need their own original. In Cook County, you can request these through the county clerk's office or vital records department.

3. Petition to Probate Will and for Letters Testamentary

If there's a will, you'll file a Petition to Probate Will and for Letters Testamentary. This is the main court form that asks the judge to:

  • Accept the will as valid
  • Appoint you (or another named person) as the executor
  • Issue Letters Testamentary, which give you legal authority to act on behalf of the estate

This petition includes information about the deceased person, the will, the nominated executor, the estimated value of the estate, and the names and addresses of all heirs and beneficiaries.

4. Petition for Letters of Administration (If There Is No Will)

When someone dies without a will (called dying "intestate"), you instead file a Petition for Letters of Administration. This is similar to the petition above, but instead of asking the court to validate a will, you're asking to be appointed as the administrator of the estate. Illinois law sets a priority order for who can serve typically the surviving spouse, then adult children, then other relatives.

Understanding the differences between these two petitions is a key part of handling executor paperwork requirements step by step.

5. Oath of Office

Before the court will issue Letters Testamentary or Letters of Administration, you must sign an Oath of Office. This is a sworn statement that you'll faithfully perform your duties as executor or administrator. In Cook County, this is usually filed at the same time as your petition or immediately after the court approves your appointment.

6. Published Notice to Creditors

Illinois law requires that you publish a notice to creditors in a newspaper in Cook County once a week for three consecutive weeks. This gives any creditors the chance to file claims against the estate. You'll need to file a copy of the published notice and proof of publication with the court. This step is often overlooked by first-time executors, but it's legally required under 755 ILCS 5/18-3.

7. Order Admitting Will to Probate and Order for Letters

After your hearing, the judge will sign an Order Admitting Will to Probate (for testate estates) or an Order for Letters of Administration (for intestate estates). The court generates these, but you may need to prepare draft orders for the judge to review. Your filing process and local court procedures will determine how this works in practice.

8. Letters Testamentary or Letters of Administration

Once the judge signs the order, the clerk issues Letters Testamentary (with a will) or Letters of Administration (without a will). These are the official documents that prove you have legal authority to manage the estate. You'll use these letters to access bank accounts, sell property, transfer titles, and deal with financial institutions.

9. Affidavit of Heirship (If Needed)

In some cases especially when there's no will the court or third parties may require an Affidavit of Heirship. This sworn document identifies the legal heirs of the deceased. It's particularly useful when dealing with real estate that needs to be transferred or sold.

10. Inventory of Estate Assets

After probate is opened, you'll need to file a detailed Inventory of the deceased person's assets within 60 days of your appointment. This includes real estate, bank accounts, vehicles, investments, personal property, and any debts owed to the estate. Each asset must be listed with its fair market value as of the date of death.

11. Bond (If Required)

The court may require you to post a surety bond to protect the estate's beneficiaries and creditors. Whether a bond is required depends on what the will says (many wills waive the bond requirement) and the judge's discretion. If the estate is small or the will waives the bond, you may be able to avoid this step.

What Forms Does Cook County Specifically Use?

Cook County has its own local court rules and preferred forms. While Illinois provides standardized probate forms statewide, Cook County may have additional cover sheets, filing requirements, or formatting preferences. Here are the most commonly used forms:

  • CCP 0350 – Petition to Probate Will and for Letters Testamentary
  • CCP 0351 – Petition for Letters of Administration (Intestate)
  • CCP 0355 – Oath and Acceptance of Office
  • CCP 0505 – Inventory of Estate
  • Notice of Probate of Will – for publication
  • Supplemental Proceedings Cover Sheet – required for all filings

You can find these forms on the Cook County Circuit Court Clerk's website or at the Probate Division counter at the Daley Center. Having a complete executor responsibilities checklist makes it much easier to track which forms you've completed and which still need attention.

How Much Does It Cost to File Probate in Cook County?

Filing fees in Cook County's Probate Division are generally around $250 to $375 depending on the type of petition and the estimated estate value. Additional fees apply for certified copies of Letters, publishing notices, and other court services. These fees are paid from the estate's assets not out of your personal pocket.

Common Mistakes That Delay Probate Filing

These are the errors that slow things down most often:

  • Filing a photocopy of the will instead of the original. The court almost always requires the original. If the original is lost, expect additional hearings and legal steps.
  • Not having enough certified death certificates. Running out means ordering more and waiting.
  • Missing heir or beneficiary information. The petition requires names, addresses, and relationships of all interested parties. Incomplete information leads to continuances.
  • Failing to publish the creditor notice properly. Skipping this or using the wrong newspaper can restart the clock on creditor claims.
  • Filing in the wrong county. Probate must be filed in the county where the deceased person lived at the time of death. If they lived in Cook County, you file at the Daley Center not at a suburban courthouse unless the case is assigned there.

Many of these mistakes come down to not understanding the full scope of executor responsibilities for managing a deceased person's estate.

How Long Does It Take to Get Probate Opened?

In Cook County, if your paperwork is complete and filed correctly, you can typically get your court date within two to four weeks of filing. After the hearing, Letters Testamentary or Letters of Administration are usually issued the same day or within a few business days. However, Cook County's Probate Division handles a high volume of cases, so delays happen especially during busy periods or if the court requires additional documentation.

Do You Need a Lawyer to Open Probate in Cook County?

Illinois law doesn't technically require you to hire a lawyer, but the Cook County Probate Division strongly recommends it, and in practice, most executors benefit from legal help. Here's why:

  • Cook County's court procedures are specific and detailed
  • Judges expect filings to follow proper format
  • Contested wills or disputes among heirs can escalate quickly
  • Real estate transfers and tax filings within probate require legal knowledge

That said, for simple uncontested estates with clear wills and cooperative beneficiaries, some executors handle the initial filing on their own and hire a lawyer later for more complex matters.

Quick Checklist: Paperwork to Gather Before You File

Use this checklist to make sure you're ready before walking into the Cook County Probate Division:

  • ☐ Original will (or explanation if it's lost)
  • ☐ Certified death certificate (get at least 10–15 copies)
  • ☐ Full legal names, addresses, dates of birth for all heirs and beneficiaries
  • ☐ List of the deceased person's assets and approximate values
  • ☐ List of known debts and creditors
  • ☐ Your valid government-issued photo ID
  • ☐ Filing fee (check or money order accepted; call ahead to confirm the current amount)
  • ☐ Completed petition form (testate or intestate)
  • ☐ Oath of Office form
  • ☐ Supplemental Proceedings Cover Sheet

Print this list, check off each item as you gather it, and bring everything to your first filing at the Daley Center. Being prepared will speed up your filing and help you avoid repeat trips. For a more detailed breakdown of what comes next after filing, review this guide on the executor duties timeline and required forms in Illinois.