Supplemental Property Taxes

A supplemental or negative supplemental tax bill will arrive separately from all other property tax bills.  

Anytime a property is sold to a new owner or new construction is completed, state law says it must be reassessed by the County. That reassessment will most likely change the assessed value of your property. 

When your assessed value changes, the County must recalculate your property taxes, and when those change, we will send you a supplemental tax bill.  

The supplemental bill shows your home’s change in value from the day you closed escrow, or reported the new construction, through the end of the fiscal year, which is June 30th.   

To calculate your supplemental tax bill, subtract your home’s old value from the new market value based on the reassessment. You are taxed on that difference. Next, we prorate what you owe based on the number of months left in the fiscal year. Finally, the 1% tax rate is applied to that amount to get your supplemental tax total. 

Watch our supplemental tax bill video above for an example. 

If you don't pay your supplemental tax bill by its delinquent date, you will be charged a 10% penalty. A $10 charge is added if you are late on the second installment. If you do not pay either installment by June 30th, your property will go into "tax default," and you will be charged a 1.5% penalty per month (18% penalty per year). A $33 redemption fee will also be added to your bill.  

Supplemental bills are separate and in addition to the annual tax bills.  They are not sent to a lender for payment.  The property owner is responsible for ensuring that the supplemental bills are paid on time.

If you have questions about property valuations, visit the County Assessor’s website.  

Negative Supplemental Bills 

You will receive a negative supplemental tax bill if your new assessment is lower than your prior-assessed value, if you get a senior citizen’s transfer of Proposition 13 values, or if you have another downward assessment. The negative supplemental will include a refund check, which can be applied to any other open bills you may have on your parcel.   

A negative supplemental bill does not change your responsibility to pay all other property tax bills.