In most states, you must prove that your marriage has permanent issues or that one party wants to leave the other party in order to file for a legal separation. The primary reason for this is that it is not required to file for legal separation in order to file for divorce. Most couples who file for legal separation are either hoping that they can work on their marriage in attempt to save it, or are concerned about protecting their interests during the separation while they prepare the final details for their divorce decree. To file for legal separation, the parties must provide a valid petition to the appropriate family court. If the couple does not agree to legally separate, the case will go to court to be heard in front of a judge.