California Code, Labor Code - LAB § 5501.5

(a) The application for adjudication of claim shall be filed in any of the following locations:

(b) If the county selected for filing has more than one office of the appeals board, the application shall be filed at any location of the appeals board within that county that meets the criteria specified in subdivision (a). The written consent of the employee, or dependent of a deceased employee, to the selected venue site shall be filed with the application.

(c) If the venue site where the application is to be filed is the county where the employee's attorney maintains his or her principal place of business, the attorney for the employee shall indicate that venue site when forwarding the information request form required by Section 5401.5. The employer shall have 30 days from receipt of the information request form to object to the selected venue site. Where there is an employer objection to a venue site under paragraph (3) of subdivision (a), then the application shall be filed pursuant to either paragraph (1) or (2) of subdivision (a).

(d) If there is no appeals board office in the county where venue is permitted under subdivision (a), the application shall be filed at the appeals board office nearest the residence on the date of filing of the injured employee or dependent of a deceased employee, or the nearest place where the injury allegedly occurred, or, in cumulative trauma and industrial disease claims, where the last injurious exposure occurred, or nearest the location where the attorney of the employee maintains his or her principal place of business, unless the employer objects under subdivision (c).