In Illinois the Court can enter a judgment declaring the invalidity of a marriage (this is a Declaration of Invalidity of Marriage, previously known as annulment).
According to the Illinois Marriage and Dissolution of Marriage Act, Chapter 40, Section 301, there are four characteristics of an “invalid” marriage:
(1) a party lacked capacity to consent to the marriage at the time the marriage was solemnized, either because of mental incapacity or because of the influence of mental incapacity or infirmity or because of the influence of alcohol, drugs, or other incapacitating substances, or a party was induced to enter into a marriage by force or duress or by fraud involving the essentials of marriage;
(2) a party lacks the physical capacity to consummate the marriage by sexual intercourse and at the time the marriage was solemnized the other party did not know of the incapacity;
(3) a party was aged 16 or 17 and did not have the consent of his parents or guardian or judicial approval; or
(4) the marriage was prohibited.
Time of commencement for a declaration of invalidity is also governed by the Illinois Marriage and Dissolution of Marriage Act. Pursuant to Section 302 of the Act:
(a) A declaration of invalidity under paragraphs (1) through (3) of Section 301 may be sought by any of the following persons and must be commenced within the times specified:
(1) for any of the reasons set forth in paragraph (1) of Section 301, by either party or by the legal representative of the party who lacked capacity to consent, no later than ninety (90) days after the petitioner obtained knowledge of the described action;
(2) for the reasons set forth in paragraph (2) of Section 301, by either party, no later than one year after the petitioner obtained knowledge of the described condition;
(3) for the reason set forth in paragraph (3) of Section 301, by the underaged party, his parent or guardian, prior to the time the underaged party reaches the age at which he could have married without needing to satisfy the omitted requirement.
(b) In no event may a declaration of invalidity of marriage be sought after the death of either party to the marriage under subsections (1), (2), and (3) of Section 301.
(c) A declaration of invalidity for the reason set forth in paragraph (4) of Section 301 may be sought by either party, the legal spouse in case of a bigamous marriage, the State’s Attorney or a child of either party, at any time not to exceed three years following the death of the first party to die.
Section 303 of the Act addresses legitimacy of children and invalidity of marriage as: Children born or adopted of a marriage declared invalid are the lawful children of the parties. Children whose parents marry after the birth are the lawful children of the parties.
Sections 304 and 305 of the Act cover retroactivity and putative spouses. Section 306 of the Act specifies that actions for declaration of invalidity of marriage shall be commenced as in other civil cases.