Boats and Aircraft

General Information for Airplane and Boat Owners

Like Real and Business Personal Property, the California Constitution and the Revenue and Taxation Code state that Boats and Non-Commercial (Private) Aircraft are also taxable property and assessable by the Assessor’s Office to their owners as of January 1 of each year (Lien Date).

Boats and Aircraft are considered movable property and the taxable situs is determined by the following criteria:

BOAT:  Taxable situs is where the boat is habitually moored when not in service.  Domicile of the owner is also used as the tax situs if the boat does not have a permanent mooring or storage location.  Registration information on boats from Department of Motor Vehicles can also be used to determined situs as of the Lien Date. 

AIRCRAFT:  Situs is the location of the airport where the aircraft is habitually situated or spends the most time in California when not in flight.  However, the assessment may be allocated if the aircraft can established tax situs outside California.  FAA registration information can also be used to determine taxable situs.  

If a Boat or Aircraft is sold after January 1, the SELLER by law is still the ASSESSEE and is responsible for the property tax assessment for that year.  


Boats and Non-Commercial Aircraft are valued at their Fair Market Value (FMV) as of January 1 of each year.  The Assessor’s Office primary uses Price Guides as the main source of market value data.   In addition, purchase price information reported on the annual Vessel or Aircraft Property Statements (FORM 576D AND 577) might be considered as a market price indicator.

For Boats with aggregate costs of less than $100,000, once the initial market value is determined and put on the assessment roll, the State Board of Equalization provides annual Vessel Adjustment Factors which are applied to the prior year assessment to derive the current year assessment. These factors are also based on the retail market studies conducted by the State Board annually to determine the adjustment basis.

Price Guide retail market values may be further adjusted by information reported on the Property Statements such as additional equipment and condition.  

A taxpayer can request for a no-cost review of their annual boat and aircraft valuation by submitting a Boat or Aircraft Value Review Questionnaire to the Marine and Aircraft Division by September 30, annually.  Additional documentation such as purchase agreement, repair estimates, and pictures of the subject property may be required to complete the value review.  A taxpayer can also file a formal Assessment Appeal with the Contra Costa County Assessment Appeals Board by November 30 of each year, if the Assessor’s Office is unable to resolve the valuation differences after the review.




If you have any questions about your Boat or Aircraft valuation, please contact our Marine and Aircraft Division at (925) 313-7605 or send us an email (please include Boat Account/CF Number or Aircraft Tail (N) Number):  [email protected]

For questions on payment of your Boat and Aircraft tax bills, please contact the Contra Costa County Treasurer-Tax Collector at (925) 608-9500.