An annulment is a legal proceeding that declares the marriage invalid or void from the beginning. It is as if the marriage never actually happened. There is no time limit for obtaining an annulment in New York, however the action in court to obtain an annulment must be commenced within two years from the date of separation.

There are many reasons for applying for an annulment. Many people seek to have a marriage annulled because they do not believe in divorce for religious reasons, or they do not want the stigma of having been divorced.

Before a marriage is recognized by the state, there must be consent or agreement between the parties. For consent to exist, both parties must agree to the marriage, and there must be no mistake as to the nature of the union, and no force, duress or undue influence must be used on either party to get married.

The most frequent reason for annulment applications is that consent for the marriage was obtained by force, fraud or duress. Examples include marrying solely to obtain legal immigration status in the US, claiming to want children when there is no desire to have children, or claiming to be pregnant to entice someone to marry. Other reasons include lack of capacity to give consent to get married, due to mental incapacity at the time of the marriage, lack of physical capacity to consummate the marriage unknown at the time of the marriage, incurable mental illness for more than five years without the possibility of a cure, or if one party is under 18 years of age at the time of marriage who has not obtained the consent of both parents, the marriage may be annulled only until the underage spouse is of legal age and cohabites with the other spouse. Also, if one of the spouses is already married at the date of the marriage and has not yet obtained a divorce from the first marriage.

The procedures for applying for an annulment in New York are the same as in a divorce application. A Summons with Notice for Annulment is filed with the County Clerk, and must be personally served on the Defendant within 120 calendar days from the filing date. Property division, maintenance, child support and custody issues must be addressed as in a divorce case. Unlike divorce proceedings, a witness Affidavit must be presented corroborating the Plaintiff's grounds for bringing the annulment application, such as supporting the allegation that prior to the marriage, the Defendant spouse promised to have children, then reneged on this promise after the marriage was solemnized.