An annulment isn't a quick divorce. It's a finding that your marriage never legally existed, and that changes what a court can do for you afterward.
Missouri courts grant annulments only if your marriage was never legally valid. Acceptable reasons ("grounds") for an annulment include bigamy, incest, lack of capacity to consent, or fraud affecting the core of the marriage. To get an annulment, you'll file in the circuit court where you or your spouse lives. You must be prepared to prove your grounds.
Annulment isn't the same as divorce. A divorce ends a valid marriage, while an annulment declares the marriage never legally existed. Below, we cover who qualifies, what happens after an annulment, and how filing works.
What Are the Grounds for an Annulment in Missouri?
Missouri presumes marriages are valid, so courts view annulment requests skeptically. There are two types of invalid marriages:
- A void marriage, such as a bigamous or incestuous one, was never a marriage at all.
- A voidable marriage, such as one that was induced by fraud or duress, is valid until a judge says otherwise.
A marriage can be invalid for any of the reasons below.
Bigamy
A marriage is void if either spouse had a living husband or wife at the time of the ceremony, unless that earlier marriage was legally dissolved. (Mo. Rev. Stat. § 451.030 (2026).)
Underage Marriage
As of August 28, 2025 you must be 18 to legally marry in Missouri. Under the earlier law, 16- and 17-year-olds could marry with written parental consent, so your wedding date decides the rules. (Mo. Rev. Stat. § 451.090 (2026).)
Kinship
Marriages between parents and children, grandparents and grandchildren of any degree, siblings of half or whole blood, aunts and nephews, uncles and nieces, and first cousins are presumed to be void. (Mo. Rev. Stat. § 451.020 (2026).)
Lack of Capacity
A judge will presume a marriage is void if—at the time of the ceremony—one spouse lacked the capacity to enter a marriage contract, whether from mental illness, cognitive decline, or another condition. However, if a court with jurisdiction over that person approved the marriage beforehand, this ground isn’t available. (Mo. Rev. Stat. § 451.020 (2026).)
Common-Law Marriage
Common-law marriages formed in Missouri have been null and void since 1921, though the state might recognize one formed while the couple lived in a state that allows them. A short trip to such a state won’t be enough. (Mo. Rev. Stat. § 451.040 (2026); Hesington v. Estate of Hesington, 640 S.W.2d 824 (Mo. Ct. App. 1982).)
Duress or Fraud
A court can set aside a marriage if one spouse was under duress—that is, coerced into going through with it. Fraud is harder to prove. To qualify, the hidden fact must involve something fundamental to the marriage. For example, Missouri courts have annulled marriages where a spouse hid a serious communicable disease, and where one hid an inability to consummate the marriage. (Watson v. Watson, 143 S.W.2d 349 (Mo. Ct. App. 1940); Kshaiboon v. Kshaiboon, 652 S.W.2d 219 (Mo. Ct. App. 1983).) Ordinary dishonesty about money, character, or past relationships won’t meet the standard for fraud. (Woy v. Woy, 737 S.W.2d 769 (Mo. Ct. App. 1987).)
You can also lose the right to annul by "ratifying" the marriage. If you keep living with your spouse after learning of the fraud, a court might treat it as condoned. (Woy, 737 S.W.2d at 772.)
What Happens After a Missouri Annulment?
When a judge grants an annulment, the law treats the marriage as though it never happened, and both spouses return to single status. Because there was never a valid marriage, there's no marital estate to divide. (Missouri's property-division and maintenance (alimony) statutes cover dissolution and legal separation, not annulment.) In fact, one Missouri court warned that annulment can leave a spouse with nothing, forfeiting rights they'd have in a divorce. (Woy, 737 S.W.2d at 774.) A court might order temporary support or lawyers' fees while the case is pending, but you shouldn’t count on it. You can ask a lawyer what’s typical in your county (see below).
Children are protected either way, and those of an annulled marriage are legitimate. (Mo. Rev. Stat. § 474.080 (2026).) A man is presumed to be the father of a child born during the marriage or within 300 days after an annulment. (Mo. Rev. Stat. § 210.822 (2026).) A court can still order custody, parenting time, and child support, and the child can inherit as though the marriage were valid.
How Do I Get an Annulment in Missouri?
Either spouse can file for an annulment without a residency waiting period. (As with property division, Missouri’s 90-day residency rule applies to divorce and legal separation, not annulment.) You must file in the county where you or your spouse lives. (Mo. Rev. Stat. § 452.300 (2026).)
To proceed, you must:
- File a petition. File in your local circuit court, stating your grounds and supporting facts. If you need temporary support for yourself or any children from the marriage, ask for that too.
- Notify your spouse. You must officially deliver notice of the case to your spouse, a step called "service of process." The circuit clerk can explain your options, including how to serve an out-of-state spouse.
- Prove your case at a hearing. You’ll need to show the judge that your marriage qualifies for an annulment, so come prepared to present your case. If the court finds valid grounds, it will declare the marriage invalid.
The burden of proof falls on the spouse who files, and Missouri courts scrutinize these requests closely. Because the stakes are high and the standards are demanding, it’s wise to talk to a lawyer before you file.
Where to Find Annulment Forms and Legal Help in Missouri
Missouri doesn't publish a statewide annulment form, so procedures vary by circuit. Ask a lawyer or the circuit clerk what an annulment requires. You might qualify for free or low-cost legal help through Legal Services of Missouri, or you can talk to a local family law attorney.
