The reasons for marriage annulment in Illinois are very specific......so if one of these applies move quickly: - one of the parties lacked capacity to consent to the marriage because of mental incapacity or infirmity (e.g., dementia, retartdation or intoxication by alcohol or drug induced haze) or was induced by fraud to marry by force or duress or by fraud involving the "essentials of marriage"; (this has to be done within 90 days of the marriage or the petition is timebarred) - a party cannot consummate the marriage by sexual intercourse and the other party did not know of the inability; (this has to be done within 1 year of the marriage or it is timebarred) - a party was aged 16 or 17 years and did not have the consent of his parents or guardian or judicial approval; (this has to be done before the minor turns to the age of majority or it is timebarred) -the marriage is otherwise legally prohibited (like one party was already married and kept that from the spouse) etc.... Also, your spouse cannot claim a common law marriage as that legal theory has been outlawed in Illinois since 1905. So, seek a court declaration RIGHT AWAY for an annulment. The time limit is strictly applied so you may have to do a divorce.