Navigating property assessment can feel overwhelming — unfamiliar language and technical jargon can make the process confusing. This glossary is designed to help property owners, taxpayers, and community members better understand the terminology commonly used in assessment notices, appeals, and related documents.

Whether you're reviewing your property's assessed value for the first time or preparing for an appeal, these plain-language explanations are here to make the process more accessible and transparent.

The terms defined here are for informational purposes only. While we've worked to make assessment language easier to understand, these explanations do not replace official legal definitions and should not be relied upon as legal advice.

Taxes imposed on the basis of the property’s value.

The taxable value of a property against which the tax rate is applied.

Due process initiated by taxpayer if the assessed value of their property cannot be agreed upon with the Assessor.

A three-member panel appointed by the Board of Supervisors to resolve disputes between the Assessor’s Office and property owners.

The official list of all property within the County assessed by the Assessor.

The fair market value of a property at the time of the 1975 lien date, or on the date of subsequent new construction or change in ownership.

Property which is moveable and not affixed to the land, and which is owned and used to operate a business, such as machinery, equipment, computers, furniture and supplies.

A transfer of real property resulting in the transfer of the present interest and beneficial use of the property.

Assessments levied outside the normal assessment period for the lien date(s) in question.

Qualifying transfers of real property which are excluded from reappraisal if a timely claim is filed with the Assessor’s Office.

Legally qualified deductions from the taxable assessed value of the property.

A property’s base value, adjusted annually by the change in the CCPI, not to exceed 2%. It is the upper limit of taxable value each year.

The period beginning July 1 and ending June 30.

Tangible property securely affixed to real property.

The amount of cash or its equivalent value that property would bring if exposed for sale in the open market, and as further defined in Revenue and Taxation Code 110.

Buildings or structures generally attached to the land.

The amount owed and created by the assessment of property, or the amount levied against the property by a taxing agency or revenue district.

The date when taxes for any fiscal year become a line on the property. The Lien Date for California property is January 1.

The construction of new buildings, additions to existing buildings, or alterations which convert the property to another use or extends the economic life of the unit.

Any property except real estate, including airplanes, boats, and business property.

Interest of a lessee in a government-owned property. Examples of a PI include the exclusive right to use public property at the harbor, wharf, parklet, state parks, etc.

Passed by California votes in June 1978, Proposition 13 is a Constitutional amendment that limits the taxation of property and creates a procedure for establishing the current taxable value of locally assessed real property.

Passed by California voters in November 1978, Proposition 8 requires the temporary reduction in the assessed value when there is a decline in market value below the property's factored base year value.

Passed by California voters in November 2020, Proposition 19 generally expands the ability to transfer assessed value and narrows property tax benefits for intergenerational transfers. New transfer provisions were added for victims of disasters and the severely handicapped.

Land that has been legally defined and improvements that have been made to the land.

Assessment roll on which the taxes are secured by lien against the real estate.

Direct charges or flat fees against property which are included in the total tax bill, but are not based upon the Assessor’s valuation of the property.

Upon a change of ownership or completion of new construction, a supplemental assessment is issued in addition to the annual regular assessment and is based on the net difference between the previous assessed values and the new value for the remainder of the assessment year(s).

The ratio of the tax to the tax base. The minimum ad valorem property tax rate is 1% of the net taxable value of the property. The total tax rate may be higher due to voter-approved general obligation bonds that are secured by property taxes for the annual payment of principal and interest.

A geographic area having the same property tax allocation factors.

Change in ownership or change in manner in which the property is held.

Assessment roll consisting largely of business personal property on which the property taxes are not secured by a lien against the real estate.