California Code of Civil Procedure > Code Civ. Proc. §116.370. Venue
(a) Venue in small claims actions shall be the same as in other civil actions.
(b) A defendant may challenge venue by writing to the court and mailing a copy of the challenge to each of the other parties to the action, without personally appearing at the hearing.
(c) In all cases, including those in which the defendant does not either challenge venue or appear at the hearing, the court shall inquire into the facts sufficiently to determine whether venue is proper, and shall make its determination accordingly.
(1) If the court determines that the action was not commenced in the proper venue, the court, on its own motion, shall dismiss the action without prejudice unless all defendants are present and agree that the action may be heard.
(2) If the court determines that the action was commenced in the proper venue, the court may hear the case if all parties are present. If the defendant challenged venue and all parties are not present, the court shall postpone the hearing for at least 15 days and shall notify all parties by mail of the court’s decision and the new hearing date, time, and place.