Helpful Terms

Base Year

Under Proposition 13, the assessment year 1975-76 serves as the original base year. Thereafter, any assessment year in which real property, or a portion thereof, is purchased, is newly constructed or changes in ownership shall become the base year used in determining the full value for such real property, or a portion thereof.

Comparable Sale

A comparable sale is a property that sold not more than 90 days after the subject property (your property) in the subject's property neighborhood (same school district or close proximity). The comparable sale should have features that are similar to subject property including size, number of bedrooms and bathrooms, quality of structure, condition and lot size.

If you are providing comparable sales in support of Decline in Value (Proposition 8) then the comparable sale needs to have occurred prior to April 1 for the tax year in question, i.e., for 2010-2011 Secured Bill Tax Year you would provide comparable sales through March 31, 2010

Indexed Base Year Value

If you owned your property before March 1, 1975, the "full cash" value will be the value as it appeared on the 1975-76 assessment roll increased up to two percent per year in accordance with Proposition 13. If you acquired or constructed the property since March 1, 1975, "assessed" value is the value at the time you took title or completed construction, plus up to two percent each year thereafter.


The value of any buildings or structures existing on land, whether new or old. Improvements may also include certain commercial and industrial fixtures and some commercial farm plants or vines.

Newly Constructed

The construction of new buildings, or the alteration of existing buildings if the alteration converts the property to another use or extends the economic life of the improvements.

Personal Property

Any property that you own other than real estate. Includes airplanes, boats, business property such as supplies, office furnishings, machinery or equipment.

Secured Property

Property on which the property taxes are a lien against real estate.

Special Assessments

Direct charges against property which are included in the total amount of your tax bill but which are not property taxes in the sense of being based on the Assessor's valuation. A sewer service charge is an example of this assessment.

Special Taxing Districts

Property tax levying agencies ranging from Air Pollution Control Districts to Sanitation and Sanitary Districts, both of which provide sewer service.

Tax Rate

The County levies an ad valor-em property tax at a rate equal to one percent of the full cash value. In addition, the rate will include an amount equal to the amount needed to make payments for the interest and principal on general obligation bonds or other indebtedness approved by the voters.

Unsecured Property

Property on which the property taxes are not a lien against real estate (office furniture, machinery, equipment, boats, airplanes, etc.). Note: business inventory is exempt from taxation.