Supplemental Tax Estimator

Richard N. Benson, Assessor - Recorder - County Clerk

The Marin County Assessor – Recorder- Clerk is pleased to announce that there is a new application available for use called the Marin County Supplemental Tax Estimator. This application is designed to help new and prospective homeowners reduce confusion concerning the amount of property taxes they can expect to pay following their purchase.

The Marin County Assessor Supplemental Tax Estimator provides an estimate of the amount of supplemental taxes a taxpayer may anticipate. The supplemental tax bill is in addition to the annual tax bill. The purpose of this Supplemental Tax Estimator is to assist the taxpayer in planning for his/her supplemental taxes while waiting for their actual supplemental tax bill. It is not intended as a legal notice of supplemental taxes due. The estimator is intended for changes in ownership only.

There are a number of situations in which the Supplemental Tax Estimator will not be able to produce a reliable estimate. The most common are:

  • More than one change in ownership has occurred in a calendar year.
  • A change in ownership and new construction has occurred in a calendar year.
  • Partial interest transfers where less than 100% of the property has been reassessed.
  • New housing tracts or condominium subdivisions in which the map recording and change in ownership has occurred in the same calendar year.

If you have an unusual situation such as one listed above or have additional questions about supplemental tax assessments, please contact the Marin County Assessor's Office by phone: (415) 473-7215, or email.