Detailed Answer

If someone lists the wrong siblings or other heirs in probate paperwork in Illinois, you can usually fix the record by asking the probate court to correct the filings. The Illinois Probate Act governs probate procedure and gives the court authority to amend pleadings, correct clerical errors, and determine the proper heirs. See the Illinois Probate Act: 755 ILCS 5/ (Probate Act of 1975).

Typical steps to correct a mistaken list of siblings

1. Confirm the mistake and gather documents. Collect evidence that shows who the legal heirs really are: birth certificates, marriage certificates, adoption records, death certificates, the decedent’s will (if any), and any other family records. If names were misspelled, get documents that show the correct legal name.
2. Contact the probate clerk. Call or visit the county probate clerk where the estate was opened. Ask what local form or procedure the court uses to correct pleadings or amend the record. Clerks can explain filing fees, required forms, and whether a hearing is usually needed.
3. File a petition or motion to correct/amend. In most Illinois probate courts you will file a short petition or motion asking the court to: (a) correct clerical errors in the original filing, or (b) allow an amended petition for letters or amended list of heirs. In the petition explain the mistake, attach supporting documents, and request the specific correction (for example, replace incorrect sibling B with correct sibling D).
4. Give notice to interested persons. Illinois probate procedure requires notice to interested parties (heirs, beneficiaries, and the personal representative). The court will tell you whom to notify and how (personal service or mail). Providing proper notice helps avoid later challenges.
5. Attend any hearing and present evidence. The court may schedule a hearing. Be prepared to explain how the mistake happened and to present your documents. If another party objects, the judge will decide based on the evidence.
6. Obtain a court order and update records. If the judge grants your petition, the court will enter an order correcting the record. File the order with the probate clerk. Ask the clerk to update case documents, the case inventory, and any certificates of heirship or letters previously issued.
7. Correct related documents and third parties. After the court order, provide certified copies to banks, title companies, Social Security, and any other institutions that were relying on the incorrect paperwork so they can update their records (for example to change beneficiary/ownership information).

Special situations and tips under Illinois law

• If the mistake is purely clerical (e.g., a typo or swapped names) the court often treats it as a clerical correction and the process is quick.
• If the error affects who the legal heirs are (for example a sibling was omitted or a non-relative was listed), the court will treat it as a substantive issue and require evidence of family relationships before changing the record.
• If someone was improperly appointed as personal representative because of the mistake, an interested party can file a petition to remove or replace that personal representative under the Probate Act. See the Probate Act for court authority to supervise administration: 755 ILCS 5/.
• If a will was admitted and the list of heirs affects distribution, the court may need to resolve the dispute before distributions continue.
• If paternity or adoption issues affect heirship, the court may require additional proceedings (such as a paternity or legitimacy determination) before changing the probate record.

Example (hypothetical)

Maria filed probate after her father died and listed siblings Anna, Ben, and Carla. Later Maria discovered Ben is actually the decedent’s nephew and the decedent’s true sibling is David. Maria should collect birth records showing the correct relationships, file a petition to amend the list of heirs, notify Anna, Carla, David, and any other interested parties, and attend the hearing with the records. If the court approves, it will issue an order correcting the estate records and the clerk will update the file.

When to hire an attorney

Hire an Illinois probate attorney if the correction involves contested heirship, removal of a personal representative, complex assets, or if another party opposes your correction. An attorney can draft the petition, calculate proper notice, present evidence at a hearing, and help you obtain certified court orders for third parties.

Potential consequences of not correcting errors

• Misdistributed assets or transfers to the wrong people.
• Claims against the estate later by the omitted or wrongly named heirs.
• Exposure of a personal representative to liability if they follow incorrect paperwork.

For general statutory background, see the Illinois Probate Act: https://www.ilga.gov/legislation/ilcs/ilcs3.asp?ActID=2108&ChapterID=60.

Helpful Hints

• Act quickly. Correcting records early avoids larger disputes later.
• Keep originals and certified copies of vital records (birth, death, marriage, adoption).
• Ask the probate clerk which local forms to use—court practices vary by county.
• Provide clear, chronological documentation showing why the original entry is wrong.
• When possible, get signed affidavits from family members who can confirm relationships.
• Serve notice to all interested parties exactly as the court requires to prevent procedural delays.
• If unsure, schedule a short consultation with a probate attorney to confirm the right filing and notice steps.