California Property Tax Assessors

Contra Costa County, California Tax Assessors' Office

Contra Costa County Assessors Phone Number
Contra Costa County Assessor
2530 Arnold Drive, Suite 100
Martinez, California 94553
Contra Costa County Assessors Fax Number 925-313-7488 (Fax)

Where is the Contra Costa County Tax Assessor's Office?

The Contra Costa County Tax Assessor Office is located at 2530 Arnold Drive, Suite 100 in Martinez, California.

What can the Contra Costa County Assessor's Office do for me?

The Contra Costa County Tax Assessor's Office oversees the appraisal and assessment of properties as well as the billing and collection of property taxes for all taxable real estate located in Contra Costa County.

Contact the assessor's office if you need help with paying your property taxes, applying for a homestead exemption or other tax exemption, reporting upgrades to your home, appealing your property tax assessment, or verifying your property records.

Submitting a Contra Costa County property tax appeal

If you believe that your house has been unfairly overappraised (i.e. appraised at a value higher than the true market value of the property), you can attempt to get your home re-appraised at a lower value by contacting the Assessor's Office to submit a property tax appeal.

You will have to submit a form describing your property and sufficient proof that it is overassessed, including valuations of similar homes nearby as evidence. If your appeal is accepted, your home assessment (and property taxes) will be lowered as a result.

If you would like to appeal your property, call the Contra Costa County Assessor's Office at (925) 313 7400 and ask for a property tax appeal form. Keep in mind that property tax appeals are generally only accepted in a 1-3 month window each year.

For more information and example appeals, see how to appeal your property taxes.

Useful Contra Costa County Facts:

The median home value in Contra Costa County is between $542,943.00 and $553,457.00. Property tax rates are based on property values.

How can I contact Contra Costa County?

You can try contacting the Contra Costa County local government directly with any issues the Assessor's Office can't solve. In many counties, certain property records such as deeds are kept in the county courthouse or county archives instead of at the tax assessors' office.

The county seat for Contra Costa County is located in the in Martinez, which is located at 651 Pine St Fl 11. You can direct your general inquiries to Contra Costa County with the contact info listed below.

Contra Costa County Phone Number


Contra Costa County Fax Number


Contra Costa County Address

651 Pine St Fl 11
Martinez, CA 94553-1229