Cal. Civ. Proc. Code § 116.370

(a) Venue and court location requirements in small claims actions shall be the same as in other civil actions. The court may prescribe by local rule the proper court locations for small claims actions.
(b) A defendant may challenge venue or court location 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 court location or appear at the hearing, the court shall inquire into the facts sufficiently to determine whether venue and court location are proper, and shall make its determination accordingly.
1. (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. If the court determines that the action was not commenced in the proper court location, the court may transfer the action to a proper location pursuant to local rule.
2. (2) If the court determines that the action was commenced in the proper venue and court location, the court may hear the case if all parties are present. If the defendant challenged venue or court location 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.