Determine if you have grounds for annulment. This might involve consulting with an attorney so you can be sure. California law recognizes eight reasons you can annul your marriage. If you or your spouse were already married at the time you married each other, you can ask for an annulment either on grounds of bigamy -- if you knew about the situation -- or on grounds that there was a “prior existing marriage,” if you believed the marriage ended by death or divorce, only to find out later that you were wrong. You can file for annulment if you and your spouse are blood relatives, if one of you was under 18 years old and didn’t have parental permission to marry, if one of you was of unsound mind or impotent, or if your spouse threatened or tricked you into marriage. You’ll have to prove these grounds later, at trial.
Begin the process of filing for annulment within the allowed time period. California law does not include a residency requirement for annulments, so you don’t have to live in the state for any particular length of time before you can file. However, you can’t file after four years have passed since the date of your marriage.
Go to California’s state court website and access Form FL-100, a family court petition. You’ll use the same petition for an annulment as you would for a divorce. However, when you complete the petition, check the box at the top for “nullity of marriage,” not “dissolution of marriage,” which is the box you would use to request a divorce.
Download and complete forms for a declaration and an attached declaration from the state court website. These are Forms MC-030 and MC-031. Use them to explain the grounds on which you’re filing for annulment. For example, you can tell the court that your spouse told you he was divorced but he was not, or that he lied to you about something so important, you wouldn’t have married him if you had known the truth.
Download Form FL-110, a summons. This form is a notice for you and your spouse, warning you that there are certain things you can’t do after you file your petition with the court. These include changing any insurance policies or selling assets. The only portions you have to fill in on the summons are the names of you and your spouse, and your spouse’s contact information, including his address.
File your three documents with the court in the county where either you or your spouse are currently living. You’ll need your original documents and at least one copy. The court clerk will review them to make sure they’re complete, file the original, and return the copies to you, marked that you’ve successfully filed them.