To get an annulment in Illinois, you file a Petition for Declaration of Invalidity of Marriage in the circuit court, prove one of four narrow legal grounds, and do it within the deadline that applies to your ground. Illinois does not call this an annulment in its statutes; the formal name is a declaration of invalidity of marriage, and the effect is stronger than a divorce: the court treats the marriage as though it never legally existed.
Do You Qualify? The Four Grounds
Illinois recognizes only four reasons to declare a marriage invalid. If your situation doesn’t fit one of them, divorce is your only option.1Justia Law. Illinois Code 750 ILCS 5 – Part III Declaration of Invalidity of Marriage
- Lack of capacity or consent. One spouse could not meaningfully consent because of mental incapacity, intoxication, or the influence of drugs. The same ground covers marriages entered into by force, duress, or fraud that goes to the essentials of the marriage. Ordinary disappointments won’t qualify. Concealing an inability to have children, or hiding an existing marriage, is the kind of fraud that will.
- Inability to consummate. One spouse physically cannot consummate the marriage through sexual intercourse, and the other spouse didn’t know about it when they married.
- Underage marriage without approval. One spouse was 16 or 17 and married without parental or guardian consent and without a court order approving the marriage.
- Prohibited marriage. The marriage was illegal because one spouse was already married to someone else, or because the spouses are too closely related. Illinois bars marriage between ancestors and descendants, siblings (including half-siblings and adoptive siblings), aunts or uncles and their nieces or nephews, and first cousins. First cousins may marry only if both are 50 or older, or if one provides a physician’s certificate confirming permanent sterility.
Deadlines by Ground
Most annulment cases fail on timing. Each ground carries its own deadline, and the clock generally runs from when you learned about the problem, not from the wedding date.1Justia Law. Illinois Code 750 ILCS 5 – Part III Declaration of Invalidity of Marriage
- Lack of capacity, force, duress, or fraud: file within 90 days of learning about the condition.
- Inability to consummate: file within one year of learning about the condition.
- Underage marriage: the petition must be filed before the underage spouse turns 18. Only the underage spouse, a parent, or a guardian can file.
- Prohibited marriage: a petition can be filed at any time, including up to three years after the death of the first spouse to die. Either spouse, the legal spouse in a bigamy situation, the State’s Attorney, or a child of either party can bring the action.
For every ground except a prohibited marriage, neither spouse can seek an annulment after the other spouse dies. That deadline is absolute. Miss the applicable deadline on any of the other grounds and the marriage remains legally valid, leaving divorce as the only route out.
Where to File
Illinois requires 90 days of residency before filing for divorce,2Illinois General Assembly. Illinois Code 750 ILCS 5/401 but annulment actions follow the rules for ordinary civil cases rather than that divorce residency statute. You may be able to file sooner than 90 days, though you still need to file in a county where you or your spouse lives. File the petition with the Circuit Clerk’s office in that county.
Prepare and File the Petition
The document is called a Petition for Declaration of Invalidity of Marriage. Illinois has no single statewide form. Some circuit clerks provide templates on their websites, so check with the clerk in the county where you plan to file.
Your petition must include the full legal names and addresses of both spouses, the date and location of the marriage ceremony, and a clear statement identifying which of the four grounds applies. The factual narrative is the heart of the petition. Say specifically what happened and why it meets the legal standard. A general claim of fraud isn’t enough; describe what was concealed, how it goes to the essentials of the marriage, and when you discovered it.
A filing fee is due when you submit the petition. Fees vary by county. In Champaign County, for example, the fee is $306 as of 2025. If you can’t afford the fee, file an Application for Waiver of Court Fees with the court.
Serve Your Spouse and Prove Your Case
After filing, you have to formally deliver a copy of the petition and a court-issued summons to your spouse. This is service of process, and it must be done by a sheriff or licensed process server. You cannot hand it over yourself. Your spouse then has 30 days from the date of service to respond.
At the hearing, you carry the burden of proof. The judge won’t take your word for it. Bring evidence tied to your ground: medical records showing incapacity, witness testimony about the circumstances of the ceremony, documents proving a prior undissolved marriage, or proof of what was concealed in a fraud case. If the judge finds the evidence sufficient, they will sign a Judgment of Declaration of Invalidity of Marriage. A certificate is then filed with the Illinois Department of Public Health.3Illinois General Assembly. Illinois Code 750 ILCS 5/707
What the Judgment Does to Property, Support, and Children
This part catches people off guard. By default, Illinois courts declare the marriage invalid as of the wedding date, meaning the marriage is treated as though it never existed. When the judgment is retroactive that way, the divorce rules for dividing property, awarding maintenance, and allocating parental responsibilities do not apply.1Justia Law. Illinois Code 750 ILCS 5 – Part III Declaration of Invalidity of Marriage
The court can choose to make the judgment non-retroactive when the interests of justice require it, such as when the couple has children or has accumulated significant shared assets. Only then do the standard dissolution rules for property division, maintenance, and child support apply. If you need the court to address any of these issues, ask specifically for a non-retroactive judgment in your petition or at the hearing.
Children born during a marriage later declared invalid are the lawful children of both parents.4Illinois General Assembly. Illinois Code 750 ILCS 5/303 An annulment does not make your children illegitimate.
Health Insurance and Immigration
An annulment terminates a former spouse’s eligibility under your health plan the same way a divorce would, and it counts as a qualifying event for changing employer-sponsored enrollment. Federal employees in FEHB have 60 days after the annulment becomes final to change enrollment to Self Only or Self Plus One, and the former spouse may qualify for Temporary Continuation of Coverage or a conversion policy.5U.S. Office of Personnel Management. I’m Separated or I’m Getting Divorced Under private plans, the Department of Labor identifies divorce as a COBRA qualifying event for a covered spouse.6U.S. Department of Labor. FAQs on COBRA Continuation Health Coverage for Workers Whether an annulment triggers the same right isn’t spelled out in every plan, so notify the plan administrator promptly and ask about COBRA once the judgment is entered.
If a non-citizen spouse holds conditional permanent residency through the marriage, an annulment does not automatically end that status. A conditional permanent resident can file Form I-751 to remove conditions without the former spouse’s participation, provided they can show the marriage was entered into in good faith. USCIS treats this as a waiver of the joint filing requirement.7U.S. Citizenship and Immigration Services. Removing Conditions on Permanent Residence Based on Marriage If the annulment was granted because the marriage was a sham, USCIS is unlikely to grant the waiver.