An annulment is different from a divorce in that it treats the marriage as if it never happened.

In New Hampshire, as in most jurisdictions, marriages are either void or voidable. A void marriage is invalid at its inception. For example, if spouses-to-be are close relatives or one of the parties was underage at the time of the ceremony, the union was void from the start. Bigamy makes a marriage void because no one may have more than one spouse at a time. In the case of a void marriage, no court action is required since it never was legally valid. A person can ask for a judicial determination under Section 458 of New Hampshire's Revised Statutes if there is doubt that a marriage might be void, however. The full text of the law governing annulments in New Hampshire is found in the New Hampshire Revised Statues Annotated 458.

A voidable marriage is valid until declared invalid when it qualifies for annulment. The insanity of one partner at the time of the wedding can make a marriage voidable. Fraud by one spouse is also grounds for an annulment, if it goes to what is called the heart of the marriage; for example, fraudulently marrying - marrying without any intention to consummate the marriage or live as a married couple, for instance - makes for a voidable marriage.

Here are some of the grounds for an annulment in New Hampshire:

Once the judge issues an annulment, the marriage immediately becomes void.

Children are still considered legitimate after an annulment. This means that the father continues to be the father unless it is proven otherwise.

Since 2009, the same laws govern same-sex marriages.

The petitioner must collect any necessary evidence to support his or her allegations. No substantial evidence is required when partners file jointly (which means neither contests the case); however, if the defendant objects to the petition, the plaintiff must prove his or her case in court.

The petitioner files the State of New Hampshire Certificate of Civil Union Dissolution, Legal Separation or Annulment, which is available for Internet download or from in the county district court, where the annulment papers are filed.

An uncontested and/or joint petition for annulment moves through the court within 60 to 120 days of the filing, but contested petitions often go to trial and take many months to settle.