An annulment is a declaration by the court that two spouses were never legally married and allows some spouses to end a marriage without divorce. A marriage may be annulled when one spouse was already married to someone else, one spouse was under the age of majority and married without parental permission, the marriage was entered into under duress, fear, or fraud, one spouse lacked the mental capacity to understand the basic meaning of marriage, one or both spouses was intoxicated during the marriage ceremony and was not able to give consent and/or the spouses were too closely related to each other by blood or adoption.
Legal advice will be necessary to determine whether your marriage meets these or other grounds for annulment.