Annulment declares that the parties were never legally married because of an impediment, so that no legal marriage could have been established. An annulment differs from a divorce because it strikes out a marriage as a legal contract. Therefore, the standard for an annulment is higher than for a divorce. An annulment leaves the partners in the same position that they would have been had they never married.

The provisions for an annulment of marriage in Arizona are found in Title 25, Chapter 3, Article 1 of the Arizona Code. According to A.R.S. 25-301, an annulment requires an impediment that renders the marriage void.

Grounds for a void marriage include A.R.S. 25-101, which defines a void marriage as one "between parents and children, including grandparents and grandchildren of every degree, between brothers and sisters of the one-half as well as the whole blood, and between uncles and nieces, aunts and nephews and between first cousins" or "between persons of the same sex." A void marriage is a nullity, and though it has no legal validity, an annulment action is still necessary to establish its invalidity, and a voidable marriage continues until one partner exercises his or her right to have it annulled.

Some other examples of situations that may qualify as voidable are bigamy, one party being underage, a blood relationship, the absence of mental or physical capacity, intoxication, the absence of a valid license, duress, refusal of intercourse, fraud, and misrepresentation as to religion.

Bigamy is grounds for an automatic annulment of marriage and marriages after the first are annulled. In order for a subsequent marriage not to be subject to an automatic annulment the first marriage must end in divorce or the spouse must have died.

The jurisdictional requirements and procedure for obtaining an annulment are the same as for a divorce, as defined in A.R.S. 25-302(A). The court divides the property of the parties and determines matters concerning the children of the marriage, as described in A.R.S. 25-302(B).

Like in a divorce, in an annulment the couple must decide custody and the division of marital assets and liabilities.

Grounds for an annulment of marriage include:

Mental illness can be grounds for an annulment when it can be proven that the illness existed at the time of marriage and that it reduced his or her ability to consent to the marriage. Mental illness that develops after the marriage is subject to divorce. The temporary insanity grounds are related but difficult to prove, particularity since annulment of marriage in Arizona states that marriages made during a “lucid interval” cannot be annulled. Mental illness demands certifiable proof of confinement to a mental institution as well as that the petitioner was unaware of the condition at the time that led to the annulment.

Consent is a critical factor in determining if a marriage can be annulled. Some of the grounds for an annulment of marriage in Arizona imply that one party to the marriage could not consent to the union. This applies to both duress as well as state of mind and maturity in the case of underage marriage without parental approval. Intoxication too, would take away the ability to consent, but only if the party can prove that there was substantial intoxication at the time of the wedding ceremony.

The plaintiff makes an argument for annulment before an Arizona judge who evaluates its merit. The judge then offers the ruling on the annulment of marriage.