To enable the tax collector to collect taxes on unsecured property on or after the due date, the assessor shall deliver to the tax collector, as soon as practicable after that date, a record in writing of the assessment of the unsecured property in such form as the board may prescribe.
Source:
Section 2909.1, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC§ionNum=2909.1..