California State law requires the reassessment of secured property as of the first day of the month following an ownership change or the completion of new construction. In most cases, this reassessment results in one or sometimes two supplemental property tax bills in addition to the annual secured property tax bill.
Understanding Supplemental Property Tax
After a change in ownership or when new construction is completed, the Office of the Assessor/Recorder must determine a new base year value for the property. The new value is determined usually by the current market value of the property. Once the new value is determined, the Office of the Assessor/Recorder will send you notification of the new assessed amount.
Once the Assessor's notice is sent, a supplemental tax bill is issued to you. The supplemental tax bill calculates the tax due on the supplemental assessment. The supplemental assessment is the difference between the new value (set at the time of purchase or completion of new construction) and the old assessed value (set on January 1 of the previous fiscal year).
New value at date of purchase or completion of new construction: $600,000
-Assessed value for current fiscal year (assessed value for previous owner or
assessed value before any new construction) $400,000
Supplemental assessment value: $200,000
A new property owner may receive one or two (sometimes three) supplemental tax bills depending on the date of purchase or completion date of new construction. It is dependent on when the Assessor's roll closes for the year. Please contact the Office of the Assessor/Recorder for more information on the roll dates.
For questions about your supplemental assessment value, contact the Office of the Assessor/Recorder at (415) 554-5596.
On July 1, 1983, California State law was changed to require the reassessment of property as of the first day of the month following an ownership change or the completion of new construction. In most cases, this reassessment results in one or possibly two supplemental tax bills being sent to the property owner in addition to the annual property tax bill.