California Code, Revenue and Taxation Code - RTC § 1840

If any county, city and county, or municipal corporation desires to secure a review, equalization, or adjustment of the assessment of its property by the board pursuant to subdivision (g) of Section 11 of Article XIII of the California Constitution, it shall apply to the board for that review, equalization, or adjustment in writing on or before November 30.  If the assessment objected to is one made outside the regular period for those assessments, the application for review shall be filed with the board within 60 days from the date the tax bill is mailed to the assessee.

Every application shall show the facts claimed to require action of the board, and a copy of the application shall be filed with the assessor whose assessment is questioned.  Upon receipt of a timely application, the board shall afford the applicant notice and a hearing in accordance with any rules and regulations as the board may prescribe.  The failure to file a timely application shall bar the applicant from relief under subdivision (g) of Section 11 of Article XIII or this section.