Tax Bill and Collections

The County Assessor must annually assess all taxable property in the county to the person, business, or legal entity owning, claiming, possessing, or controlling the property on January 1st of each year, according to California State law. The following are the major property tax bill types issued against all taxable property in the county.
Property Tax Bill Types
1.  Secured Tax: Secured property taxes are calculated by the Controller-Treasurer Department based on real property’s assessed value as determined annually by the County Assessor on January 1. This date is often referred to as the Tax Lien date. Secured Property Tax bills are mailed by the Tax Collector's Office (Department of Tax and Collections) in October, using the value established on the Tax Lien date. The term "secured" simply means taxes that are assessed against real property (e.g., land or structures). The secured property tax bill is payable in two installments:  
         (a) The first installment is due and payable on November 1. December 10 is the last day to pay without penalty.
         (b) The second installment is due and payable on February 1. April 10 is the last day to pay without penalty.
If December 10 or April 10 falls on a weekend or County of Santa Clara holiday, then the deadline is extended to the next business day.
2.  Supplemental Tax: Whenever there is a reappraisal due to a change in ownership (e.g. property bought or sold) or due to the completion of new construction, state law requires that a Notice of Supplemental Assessment be issued by the Assessor's Office and sent to the owner at the address of record. Following this notice, a Supplemental Tax Bill will be issued by the Department of Tax and Collections.
The supplemental tax bill will be based on the difference between the prior value and the new reappraisal. This value is prorated* for the number of months remaining in the fiscal year (July 1 to June 30) regular tax bill. Usually, it is not prorated in escrow during purchase, nor is it paid by the lender through an impound account. Unlike the secured tax bill, lending agencies do not receive a copy of the supplemental tax bill. 
The Assessor's Office and Department of Tax and Collections recognize that receiving the Notice of Supplemental Assessment and the Supplemental Tax Bill can come as a surprise.  The online Supplemental Tax Estimator can help property owners get more information on the assessment impact of a change in ownership.
3.  Value increase or Escape bill: After a change in ownership or when new construction is completed, state law requires the County Assessor to determine a new base year value for the property. Occasionally the Assessor must make a correction to an assessed value after an assessment roll (a list of all property in the county together with their assessed values) has been completed and turned over to the Controller-Treasurer and then to the Department of Tax and Collections for billing. These corrections or changes to an assessed value result in a Notice of Escape Assessment being sent to the property owner. These corrections could be because of an error by the Assessor’s office or by the property owner. An example would be the Assessor’s office not assessing new construction in a timely manner or the property owner building an addition without obtaining a building permit, therefore, the Assessor’s office was not aware of the new construction.
Since escape assessments always deal with value that should have been assessed but was not, additional taxes will be due. Once the new value is determined, the County Assessor will send notification of the new assessed amount followed by a Secured Escape bill sent from the Department of Tax and Collections. However, the current owner will not be responsible for taxes on any escape assessment that covers a time period before they acquired the property. See R&T Code Section 531.
4.  Unsecured Tax: The term "unsecured" simply refers to property that can be relocated and is not real estate. The tax is assessed against assets such as business equipment, fixtures, boats and airplanes. An unsecured tax bill covers a fiscal year. The fiscal year begins July 1 and ends on June 30 of the following calendar year. Unsecured tax bills are due and payable on August 1, with a payment deadline of August 31.
*The Supplemental Assessment proration factor is the percentage of months remaining in the fiscal year, and then multiplied by the tax rate (usually 1% plus voter approved indebtedness) to determine the supplemental tax amount due. 
Billing and collection of all property tax bills and fines is the responsibility of the County Tax Collector in the Department of Tax and Collections.
For questions related to the contents of the Property Assessment Calendar above, click on the image to view the Office of the Assessor's Frequently Asked Questions.

Learn more

Go back to "How Does Property Tax Work?" to get an overview of the property tax process.
Go to "Where Do my Property Tax Dollars Go" to learn how these monies benefit the community.