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8:00 am - 4:30 pm

FAQs - Property Tax

How can I contact the Auditor-Controller’s Office?

We are located at:  
4080 Lemon St. 11th Floor              
Riverside, CA 92501
Telephone: (951) 955-3800
Fax: (951) 955-3802
Is there a centralized location to obtain property tax information?

The county offices of the Assessor, Auditor-Controller and Treasurer-Tax Collector created a website to assist the public with general information concerning property taxes.  To visit this site click here.

How can I obtain a copy of the tax rate book?

Copies are available for $35.00.  Please click here for a link to the form to be filled out and mailed in with your check payable to:

Riverside County Auditor-Controller’s Office
P.O. Box 1326
Riverside, CA 92502

How are property taxes calculated?

Property taxes are calculated by multiplying the assessed value by the tax rate.  For property held primarily as the residence of the taxpayer, a value of 7,000 for a homeowner’s exemption may be deducted from the assessed value to arrive at the net amount subject to property taxes.  To obtain the homeowners exemption click here for more information.

What does a Tax Rate consist of?

In California, the property tax rate is set at 1%.  This rate is constant as guaranteed under Proposition 13 passed in 1978.  What this means is that a $1 tax is imposed for every $100 of assessed value of the property.  In addition, under the provisions of Proposition 13, any taxes levied by any governmental agency on top of the 1% must be approved by 66 2/3% of the voters.  However, in the case of the school bonds, only 55% majority is required as provided for under Proposition 39.  Therefore, any rate you will see in your tax bill added to the 1%, represents a debt or debts approved by the voters.

Can my property taxes change from year to year?

Yes.  Proposition 13 allows for an increase of up to 2% of property value each year.  (Revenue and Taxation code 51)  Also, the tax rate in your area can increase as new bonds are added or decrease as existing bonds are paid off.  Special Assessments can also cause an increase or decrease as they are added or deleted.

What is a supplemental tax bill?

In addition to annual taxes, you may be responsible for paying supplemental property taxes. State law requires The Assessor's Office to reappraise property upon a change in ownership or new construction. The supplemental assessment reflects the difference between the new assessed value and the old or prior assessed value. If the property is reassessed at a higher value than the old assessed value, a supplemental bill will be issued. If the property is reassessed at a lower value than the old assessed value, a refund may be issued.


Per Revenue and Taxation Code, (RTC) 75.41, The auditor shall apply the current year’s tax rate, as defined in Section 75.40, to the supplemental assessment or assessments, computing the amount of taxes that would be due for a full year. The taxes are prorated based on the number of months left in the fiscal year from the date of ownership change or the new construction completion date. If the change in ownership or new construction occurs between January 1st and May 31st, two fiscal tax years will be computed and one supplemental tax bill will be issued. The first supplemental calculation will be for the remainder of the fiscal year, and the second supplemental calculation will be for the fiscal year that follows. 


PLEASE NOTE:  Supplemental tax bills are mailed directly to the property owner and are your responsibility. In general, they are not paid out of your impound account. Please check with your lender.

Will I get a supplemental tax (bill) every year?

No.  It is a one-time adjustment.  It only occurs when there is a change of ownership or when a new construction project is completed.  In a few instances, destruction of property due to acts of nature could lead to a negative adjustment that may result in a supplemental refund



What are special assessments?

Special assessments are additional charges attached to a tax bill levied by cities, special districts, and other governmental entities.  Special assessments are not part of the tax rates.  These assessments may include but are not limited to the following: garbage collection, weed abatements, sewer charges, maintenance fees, Mello-Roos, etc.  The calculation of these charges is the responsibility of the agency that levies them.  These special assessments are individually identified on your tax bill.  For questions regarding these special assessments, please call the telephone number of the agency that levied it.  The phone number is indicated on your tax bill corresponding to the assessment in question.

What is Mello-Roos?

The Mello-Roos Act of 1982 provides a flexible alternative method for local governments to finance public facilities.  This legislation allows cities, counties, and special districts to designate specific areas as “Community Facilities Districts” (CFD) and, with the approval of two-thirds of the qualified voters, allows these districts to issue bonds and collect special taxes to finance such projects.  The CFD may finance projects with a specific benefit to the district, such as streets, water, sewer, and drainage facilities, as well as projects of a more general nature, such as parks, schools and libraries.

How long will Mello-Roos fees last?

Generally, the bonds are paid over a period of 10 to 20 years.  To get an exact time period for your assessment, you will need to contact the agency shown on your tax bill.

How long does it take to obtain a refund?

The Property Tax Division of the Auditor-Controller's Office (ACO) issues refunds as a result of value corrections, assessment appeals and special assessment reductions.  Once these corrections are made to the tax roll, the refund is sent to the Tax Collector’s Office (TC), where a “claim for refund” is prepared and mailed to the taxpayer.  When the claim form is returned, the TC will release the refund back to the Auditor-Controller to process a refund warrant.  As a matter of policy, the refund warrant is processed within 10 working days after all steps above have been completed. 

For the following issues, please contact the agency identified on your tax bill. Phone number is next next to the charge amount.


  • What is the balance of my Mello-Roos?
  • Who shall I ask about Mello-Roos? School bond?
  • How long do I have to pay my voter approved bond?
  • How do I clear or pay my delinquent garbage bill?
  • I have a well to supply me with water. Do I still have to pay the assessment for water on my tax bill?