Cal. Elec. Code § 15320

Vote by mail ballots and mail ballot precinct ballots returned to the elections office and to the polls on or before election day that are not included in the semifinal official canvass phase of the election, including any ballots returned to another jurisdiction in the state and forwarded to the elections official who issued the ballot pursuant to Section 3017, shall be processed and counted during the official canvass in the manner prescribed by Chapter 2 (commencing with Section 15100) of Division 15, and pursuant to the requirements of Section 3019.