If a marriage is annulled, the marriage is treated as if it never existed. Marriages can be void or voidable. A marriage is voidable if: either party is under age; one or both parties lack capacity; there is no consent; fraud; mistake; force; impotency; the woman is pregnant by another; or the marriage is not consummated.

Void marriages are serious violations of public policy. A marriage is void if either of the parties is already married (bigamy), the parties are closely related (incestuous), or if either party has been adjudicated insane at the time of the marriage ceremony.