Information provided by the Supplemental Tax Calculator are estimates only based on the most current assessment roll information processed. It is designed to help homeowners budget for their property tax payments after purchase. Supplemental tax bills are prepared by the Office of the Treasurer & Tax Collector. Do not use the estimate to pay the supplemental tax bill. Use only the amount provided in the supplemental tax bill.
Please note that the calculator is intended for 100% ownership transfer only and not for new construction. Below are some of the situations in which the Supplemental Tax Calculator will not be able to produce a reliable estimate.
- 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 changed ownership.
- Subdivisions in which the map recording and change in ownership has occurred in the same calendar year.
Important Notice: Catch-up Notices of Supplemental and Escape Assessments:
Due to an unprecedented increase in workload, the Office of the Assessor-Recorder has experienced delays in processing assessable events. As a result, you may receive additional assessment notices for prior fiscal years once your reassessment is completed. These "catch-up" assessments reflect the difference between your new and old assessed values and do not increase your total property tax obligation beyond what you would have paid had your reassessment been processed on the typical timeline.
If you have additional questions about supplemental assessment, please contact assessor@sfgov.org