What is a supplemental tax bill?

The supplemental bill is for taxes on the increase in assessed value, prorated from the date of change in ownership or date of completion of construction to the end of the Fiscal Year. It is in addition to the original secured tax bill for your property. It does not replace the original bill. This bill is sent directly to the homeowner and NOT to the mortgage company.

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. What is meant by new construction is any substantial addition to real property (e.g., adding a new room, pool, or garage) or any substantial alteration which restores a building, room, or other improvement to the equivalent of new (e.g., completely renovating an outdated kitchen). In most cases, this reassessment results in one or more supplemental tax bills being sent to the property owner in addition to the annual property tax bill. 

Most changes in ownership caused by the sale of property result in reassessment. However, interspousal transfers, the transfer, sale, or inheritance of property between parents and their children, and the addition of joint tenants do not result in the reappraisal of property values. 

Furthermore, homeowners over the age of 55 years who sell their principal residence and purchase a replacement dwelling within two years that is of equal or lesser market value and is located in the same county are eligible to transfer the pre-sale assessed value of their original property to the replacement dwelling. For further information, please contact the Assessor’s Office at (925) 313- 7400. 

Show All Answers

1. What is a supplemental tax bill?
2. How is a Supplemental assessment done?
3. Do I have the same right to appeal the Assessor's supplemental assessed value as I do the annual assessed value?
4. If I receive a supplemental tax bill, will I also receive an annual tax bill in the fall of each year?
5. If I pay my property taxes through an impound account (i.e., with my mortgage payment), will my lender get my supplemental tax bill?
6. What does the supplemental tax bill tell me?
7. What if I purchase a piece of property and then sell it again after a few months?
8. When I purchase property or complete construction at some point during the Fiscal Year, will I be taxed on the supplemental value for the entire Fiscal Year?
9. Is it possible to get more than one supplemental tax bill?
10. When do supplemental tax bills have to be paid?
11. If payment of the supplemental tax bill is not made before the delinquency date because of a misunderstanding between my lender and myself, may I have the penalties excused?
12. What happens if I fail to pay my supplemental tax bill?
13. Can delinquent supplemental taxes be paid on an installment plan?
14. Am I entitled to a homeowner's exemption on my supplemental tax bill?
15. Are other exemptions and assistance programs available that will help defray the amount of supplemental taxes due?