Use our supplemental tax calculator
We created a calculator to help you understand how much money you should save to cover your new property tax bills.Use our supplemental tax calculatorWhat you need to know
Assessable events
Certain events, like a change in ownership or new construction, require our Office to reassess a property's value. Normally, we process these events and send notices within approximately 12 months, depending on when your event occurs.
Unprecedented workloads
Due to an unprecedented increase in workload over the last three years, the Office of the Assessor-Recorder has not yet reviewed all such events, creating a backlog of assessable events including the event(s) associated with your property.
What happens next
- When our office reviews your event, we'll send you one or more notices, called Supplemental and Escape Assessments, that show the corrected value for the affected tax years.
- They do not increase what you owe beyond what you would have paid if your event had been processed in the usual timeline.
Understanding your future notices
- Supplemental and/or escape assessments happen routinely after an assessable event. What's different right now is that yours is arriving later than the typical timeline due to a backlog in our office.
- Each notice will include the corrected assessed value and instructions for what to do if you disagree with it.
- These notices are not bills. Separate tax bills for any amount owed will be mailed by the Office of the Treasurer and Tax Collector.
- Supplemental assessments cover the reassessment tied to a change in ownership or completion of new construction, prorated from the date of the event forward.
- Escape assessments correct an assessed value for prior years.
While you wait
- If you recently purchased a property and are waiting to receive your new assessed value, you can use the supplemental tax calculator tool to estimate what your new assessed value and associated tax obligations will be for the fiscal year you purchased the property.
- For additional information about how property is assessed in California, you can also read our Proposition 13 explainer page.
Paying bills once they arrive
- When you receive a supplemental or escape tax bill, pay it by its due date. Under State law, late payments are subject to additional penalties.
- To understand what options there may be for payment plans and see further information about paying your property taxes, please visit the Treasurer and Tax Collector's website.
- If your new assessed value is found to be lower than your previous one, you will receive a refund from the Treasurer and Tax Collector.
How we're working to solve this problem
- For the past several years, we have used all available resources to minimize delays, including reprioritizing work, restructuring teams and workflows, and seeking additional staffing where prudent.
- As a result, we resolved over 7,500 assessment appeals last year, 400% more than pre-pandemic norms. At the same time, we completed over 13,000 assessable events, or 165% more than the previous year—measurable progress in clearing the backlog. As of August 2026, the backlog of assessable events includes 15,624 items across 2023, 2024, and 2025.
Anticipated timelines
- State law allows Assessors four years to process assessable events, recognizing that workloads can shift dramatically and rapidly with the economy, while adjusting appraiser staffing often takes far longer.
- Our current timeline for most assessable events is approximately two years, and we are working to return to the pre-pandemic timeline of one year or less.
Questions or concerns
If you have any questions or concerns, please do not hesitate to contact us:
- Online: Assessor-Recorder Community Portal or email at assessor@sfgov.org,
- Phone: 628-652-8100, or
- In person: San Francisco City Hall, Room 190, 8:00 AM to 5:00 PM.