State law requires the Assessor to reappraise property upon change in ownership or completion of new construction. The supplemental assessment reflects the difference between the new value and the old value. The Auditor-Controller calculates the supplemental property tax, and prorates it, based upon the number of months remaining in the fiscal year in which the event occurred. The fiscal year runs from July 1 through June 30.
A change in ownership or new construction completion which occurs between January 1 and May 31 results in two supplemental assessments and two supplemental tax bills. The first supplemental bill is for the remainder of the fiscal year in which the event occurred. The second supplemental bill is for the subsequent fiscal year.
Notices of Assessed Value Change are mailed to property owners before supplemental tax bills are issued. Remember that supplemental tax bills are in addition to the regular annual tax bills. Supplemental bills go directly to the property owner and not to an impound account - where one might exist.