California Code, Elections Code - ELEC § 9113

The petition shall be filed by the proponents, or by any person or persons authorized in writing by the proponents. All sections of the petition shall be filed at one time. Any sections of the petition not so filed shall be void for all purposes. Once filed, no petition section shall be amended except by order of a court of competent jurisdiction.

When the petition is filed, the county elections official shall determine the total number of signatures affixed to the petition. If, from this examination, the county elections official determines that the number of signatures, prima facie, equals or is in excess of the minimum number of signatures required, the county elections official shall examine the petition in accordance with Section 9114 or 9115. If, from this examination, the county elections official determines that the number of signatures, prima facie, does not equal or exceed the minimum number of signatures required, no further action shall be taken.