Contesting a Will in Illinois: Grounds, Timeline, and What to Expect

What is a will contest in Illinois?

A will contest is a legal action filed to challenge the validity of a will that has been admitted — or is being offered for admission — to probate. If the contest succeeds, the challenged will is set aside and the estate is administered under a prior valid will or, if none exists, under Illinois intestacy law. Will contests are adversarial proceedings with serious legal and financial consequences for all parties involved.

Grounds for contesting a will in Illinois

Illinois courts require a specific legal basis for a will contest. Dissatisfaction with the decedent's choices, however understandable, is not sufficient. The recognized grounds under Illinois law are:

•       Lack of testamentary capacity: The testator lacked the mental capacity to make a valid will at the time of execution. Illinois requires that the testator understand the nature and extent of their property, know the natural objects of their bounty, understand the nature of the testamentary act, and be able to relate these elements to form an orderly plan of disposition. Cognitive decline, dementia, or mental illness may support a capacity challenge, but the condition must have affected the testator's understanding at the specific moment of execution.

•       Undue influence: A third party so dominated or controlled the testator's decision-making that the resulting will is the product of that person's will rather than the testator's own. Illinois courts look at the totality of circumstances: the testator's susceptibility, the alleged influencer's opportunity and motive, and whether the will's terms are consistent with the testator's prior expressed intentions.

•       Fraud: The testator was induced to sign the will or make specific bequests through intentional misrepresentation of material facts.

•       Forgery: The will or the testator's signature was fabricated.

•       Improper execution: The will was not executed in compliance with the Illinois Compiled Statutes, which require the testator's signature and attestation by two or more credible witnesses in the testator's presence.

Illinois's six-month deadline: one of the shortest in the country

Illinois imposes a strict six-month statute of limitations for will contests, measured from the date the will was admitted to probate. This is among the shortest will contest windows in the United States, and Illinois courts enforce it without leniency. A contest filed even one day after the six-month period expires will be dismissed.

Critically, the deadline runs from the date of admission to probate — not from the date an interested party learns of the will or the probate proceeding. Heirs and potential contestants who are slow to investigate their options can easily lose the right to challenge simply by not acting in time. If you have any reason to question the validity of a loved one's will, consult an attorney immediately after learning of the probate filing.

How an Illinois will contest proceeds

A will contest in Illinois is filed as a separate adversarial proceeding in the Circuit Court where the estate is being probated. The contestant names the executor and all legatees under the will as defendants. The case is governed by the Illinois Code of Civil Procedure, which means the full range of civil litigation tools apply: written discovery, depositions, expert witnesses, and ultimately a bench or jury trial.

Illinois will contests frequently rely on expert testimony from physicians, neurologists, or geriatric psychiatrists who can offer opinions on the testator's mental state at the time of execution — often based on a review of medical records rather than personal examination. Attorneys who regularly handle will contests know how to develop and present this evidence effectively.

Defending against a will contest in Illinois

Executors and named beneficiaries who find themselves defending a will contest have their own set of considerations. Gathering contemporaneous evidence of the testator's capacity — notes from the drafting attorney, witness statements, medical records showing intact cognition near the time of execution — is essential. Many contests are ultimately resolved through settlement, and a well-documented defense strengthens the position of the party seeking to uphold the will.

Whether you are considering challenging a will or defending one, Illinois's six-month deadline demands immediate action. Our probate litigation attorneys handle will contests throughout Illinois and can evaluate your situation quickly. Contact us today.