An incestuous or bigamous relationship
One (or both) spouse was a minor on the date of the marriage
One lacked the mental capacity to marry (an 'unsound mind')
One spouse was physically unable to consummate the marriage
For the court to grant the annulment, the Petitioner must prove at least one of these conditions exists. This can be very difficult. If you believe you may qualify for an annulment, a competent, licensed lawyer in your jurisdiction can be a huge help.