An annulment in Illinois wipes a marriage off the books as if it never existed, but you can only get one if something was legally wrong with the marriage at the moment it began. The state calls this a “declaration of invalidity of marriage,” and it is governed by Sections 301 through 305 of the Illinois Marriage and Dissolution of Marriage Act. The grounds are narrow, the filing deadlines are short, and missing them leaves divorce as the only way out.
Grounds That Qualify
Illinois will invalidate a marriage only for reasons listed in the statute. A short marriage, a regretted marriage, or a marriage that simply stopped working does not qualify.
- Lack of capacity to consent at the time of the ceremony, whether from mental incapacity, intoxication, or another incapacitating condition.1Illinois General Assembly. Illinois Compiled Statutes 750 ILCS 5/301 – Prohibited Marriages
- Force or duress used to push a spouse into the marriage.
- Fraud that goes to the essentials of the marriage. Courts look for deception about something central to the marital relationship itself, such as hiding a prior undissolved marriage or concealing an inability to have children. Lies about income or peripheral matters usually will not suffice.219th Judicial Circuit Court, IL. Types of Family Law Cases – Section: Declaration of Invalidity of Marriage
- An underage spouse who was 16 or 17 at the wedding and lacked consent from both parents, a guardian, or a judge.3Illinois General Assembly. Illinois Compiled Statutes 750 ILCS 5/203 – License, Medical Examination and Fee
- A prohibited marriage, meaning bigamy or a union between close relatives by blood or adoption.4Illinois Legal Aid Online. I Want My Marriage Annulled
Capacity, force, and fraud all require proof that the defect existed on the wedding day, not that it developed later.
How Long You Have to File
Deadlines are strict, and this is where most annulment cases collapse. The clock varies by ground.
- Incapacity, intoxication, force, or duress: 90 days from when you learn (or regain awareness) of the problem.5FindLaw. Illinois Compiled Statutes 750 ILCS 5/302 – Time of Commencement
- Fraud: one year from discovering the deception.5FindLaw. Illinois Compiled Statutes 750 ILCS 5/302 – Time of Commencement
- Underage marriage: before the underage spouse reaches the age at which they could have married without the missing consent, which in most cases means before turning 18. The petition can be filed by the minor, a parent, or a guardian.4Illinois Legal Aid Online. I Want My Marriage Annulled
- Bigamy or close relatives: any time while both spouses are alive, and within three years of the first spouse’s death.5FindLaw. Illinois Compiled Statutes 750 ILCS 5/302 – Time of Commencement
For the voidable grounds (incapacity, fraud, and underage marriage), no petition can be filed after either spouse has died.5FindLaw. Illinois Compiled Statutes 750 ILCS 5/302 – Time of Commencement
Void Marriages vs. Voidable Marriages
Bigamous marriages and marriages between close relatives are void from day one. They are invalid whether or not a court says so, but a formal declaration gives you a clean legal record. A wider group of people can bring the petition in these cases: either spouse, the legal spouse in a bigamous marriage, the State’s Attorney, or a child of either party.5FindLaw. Illinois Compiled Statutes 750 ILCS 5/302 – Time of Commencement
Voidable marriages, by contrast, are treated as fully valid until a court invalidates them. The incapacity, force, fraud, and underage grounds all fall in this category, which is why the short filing windows matter so much.
Filing the Petition
You start by filing a petition for declaration of invalidity in the circuit court of the county where you or your spouse lives. The petition must identify the specific statutory ground and lay out the facts supporting it. Filing fees vary by county and generally run around $300 or more, roughly in line with divorce filing fees.
Your spouse then has to be formally served by a sheriff, licensed process server, or another method the court approves. Handing the papers over yourself does not count.
The hearing itself is where annulment diverges sharply from divorce. You carry the burden of proof, and the other spouse can contest the petition. In a fraud case, that means showing the deception went to the essentials of the marriage. In a capacity case, medical records or witness testimony about the spouse’s condition at the ceremony usually become the core evidence. Contested cases can stretch across multiple hearings, and the evidentiary bar is higher than in a no-fault divorce, so representation matters more.
Property and Spousal Maintenance
Because the marriage is treated as if it never happened, standard marital property rules do not apply the way they would in divorce. The court’s default move is to unwind the finances: return property to whoever owned it before the marriage and adjust for each person’s contributions during the time the couple lived together. Joint accounts, shared debts, and commingled assets can complicate that unwinding, particularly if the parties were together for years.
Spousal maintenance is generally unavailable after an annulment. The important exception is the putative spouse doctrine. If you genuinely believed the marriage was valid when you entered it, the court can designate you a putative spouse and give you the same rights as a legal spouse, including property division and maintenance.6Justia Law. Illinois Compiled Statutes 750 ILCS 5 Part III – Declaration of Invalidity of Marriage – Section 305 This most often comes up in bigamy cases, where the innocent spouse had no idea their partner was already married.
Children Are Not Affected
An annulment does not change the legal status of children born or adopted during the marriage. Illinois law states directly that they are the lawful children of both parties despite the invalidity of the marriage.7Illinois General Assembly. Illinois Compiled Statutes 750 ILCS 5/303 – Legitimacy of Children Allocation of parental responsibilities, parenting time, and child support are decided using the same best-interest factors and income-shares guidelines that apply in divorce. For the children, annulment and divorce produce the same practical result.
Immigration: Annulment Is Not Divorce
If your immigration status depends on your marriage, an annulment has consequences a divorce does not. USCIS treats an annulment as retroactive: for immigration purposes, the marriage is considered never to have existed. A divorce, in contrast, acknowledges that a valid marriage existed and ended.8U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 6 Part B Chapter 6 – Spouses
Conditional permanent residents who got a green card through marriage can still file a Form I-751 waiver without the spouse after an annulment, but they must show they entered the marriage in good faith.9U.S. Citizenship and Immigration Services. Removing Conditions on Permanent Residence Based on Marriage If USCIS concludes the marriage was never genuine, immigration benefits can be revoked. If your case has an immigration angle, work with an immigration attorney alongside your family lawyer, because the two proceedings interact in ways that are easy to get wrong.