Underage

• In California, persons under 18 are incapable of legally consenting to marriage. Such a marriage can be annulled by the underaged party within four years of arriving at the age of consent, or by a parent or guardian at any time before the married minor arrives at the age consent.
  
  

Living Spouse

• A person with a spouse who was believed to be dead but was actually alive can apply for an annulment as long as either party is alive.
  
  

Unsound Mind

• If a party to the marriage is of unsound mind, annulment may be applied for by the injured party or by a relative of the person of unsound mind at any time during the life of either party to the marriage.
  
  

Fraud and Forced Marriages

• If the consent to a marriage was obtained by fraud, or either party was forced into it, annulment may be obtained within four years of the discovery of the facts constituting the fraud, or four years of the marriage (in the case of force).
  
  

Incapability

• If either party is found to have been physically incapable of entering into the marriage state -- unable to consummate the marriage -- and the incapacity seems to be incurable, annulment can be obtained within four years of the marriage.