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Frequently Asked Questions


On July 1, 1983, California State law was changed to require the reassessment of property as of the first day of the month following an ownership change of the completion of new construction.  In most cases, this reassessment results in one or more supplemental tax bills being sent to the property owner in addition to the annual property tax bill. 

Supplemental Taxes
1 How were changes in property value due to sale of property or new construction taxed in the past?
2 What do you mean by new construction or change of ownership?
3 What happens when the Assessor reassesses my property?
4 Do I have the same right to appeal the Assessor's supplemental assessed value as I do the annual assessed value?
5 If I receive a supplemental tax bill, will I also receive an annual tax bill in November of each year?
6 If I pay my property taxes through an impound account (i.e., with my mortgage payment), will my lender get my supplemental tax bill?
7 What does the supplemental tax bill tell me?
8 What if I purchase a piece of property and then sell it again after a few months?
9 When I purchase property or complete construction at some point during the fiscal year, will I be taxed on the supplemental value for the entire fiscal year?
10 So, it's possible to get more than one supplemental tax bill?
11 When do supplemental tax bills have to be paid?
12 If payment of the supplemental tax bill is not made before the delinquency date because of a misunderstanding between my lender and myself, may I have the penalties excused?
13 What happens if I fail to pay my supplemental tax bill?
14 Can delinquent supplemental taxes be paid on an installment plan?
15 Am I entitled to a homeowner's exemption on my supplemental tax bill?
16 Are other exemptions and assistance programs available that will help defray the amount of supplemental taxes due?
17 What happens if I fail to pay my taxes on time?

 

1) How were changes in property value due to sale of property or new construction taxed in the past?

Before July 1983, the Assessor reassessed property just once each year on January 1 for taxes due the following fiscal year (July 1 thru June 30).  Any change in property value resulting from a change in ownership or the completion of new construction that took place after January 1 was not reevaluated and taxed until the following year.

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2) What do you mean by new construction or change of ownership?

Typically, new construction is any substantial addition to real property (e.g., adding a new room, pool, or garage) or any substantial alteration which restores a building, room, or other improvement to the equivalent of new (e.g., completely renovating an outdated kitchen).

Most changes in ownership caused by the sale of property result in reassessment.  However, interspousal transfers, the transfer, sale, or inheritance of property between parents and their children, and the addition of joint tenants do not result in the reappraisal of property values.

Furthermore, homeowners over the age of 55 years who sell their principal residence and purchase a replacement dwelling within two years that is of equal or lesser market value and is located in the same county are eligible to transfer the pre-sale assessed value of their original property to the replacement dwelling.

For further information or claim forms, please contact the Assessor's Office at (707) 565-1888.

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3) What happens when the Assessor reassesses my property?

Assessor first determines the new value of the property based on current market values.  The Assessor then calculates the difference between the new value (set at the time of purchase or completion of new construction) and the old value (set on January 1 of the previous fiscal year).  The result is the supplemental assessment value.  Once the new assessed value of your property has been determined, the Assessor will send you a notification of the amount.

Example:
 
  New value at date of purchase or
Completion of new construction
$120,000
  Assessed value for current fiscal year
-100,000
  Supplemental assessment value will be
$ 20,000

This reassessment usually results in an increase in property value, in which case your supplemental taxes will be calculated by the Auditor-Controller based on the change in value, and one or more supplemental tax bills will be created and mailed to you by the Tax Collector.  However, in some instances the reassessment results in a reduction in value, in which case a refund will be prepared by the Auditor-Controller and mailed to you.  A reduction in value will not reduce the amount due on the annual tax bill.  The annual tax bill must be paid in the amount originally billed.

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4) Do I have the same right to appeal the Assessor's supplemental assessed value as I do the annual assessed value?

Yes. You may take the matter up with the Assessor to see if that office will change the valuation. Additionally, the Board of Supervisors has established several Assessment Appeals Boards for the purpose of resolving valuation problems in connection with supplemental tax bills. Applications for appeal must be filed within sixty days of the mailing date shown on the assessment notice. If you choose to appeal your assessment, you should still pay your tax installments in full by the appropriate deadlines; otherwise, you may incur penalties while the case is in appeals. If your appeal is granted, a refund will be issued to you.

Further information about the appeals process can be obtained from the Assessor's Office by calling (707) 565-2241 or writing to: Assessment Appeals Board, 575 Administration Dr., Room 100A, Santa Rosa, CA 95403.

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5) If I receive a supplemental tax bill, will I also receive an annual tax bill in November of each year?

Yes. The supplemental tax bill is sent in addition to the annual tax bill and both must be paid as specified on the bill.

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6) If I pay my property taxes through an impound account (i.e., with my mortgage payment), will my lender get my supplemental tax bill?

No. Unlike the annual tax bill, lending agencies do not receive a copy of the supplemental tax bill. When you receive a supplemental tax bill, you must contact your lender to determine who will pay the bill.

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7) What does the supplemental tax bill tell me?

The supplemental tax bill provides the following information:

  • The owner (or new owners as of the date of ownership change).
  • The fiscal year for which the taxes are assessed.
  • The location or address of the property.
  • The new assessed value upon which the property tax is computed, based upon the tax prorated from the event date.
  • The type and amount of any exemptions (e.g. homeowner's).
  • The total amount of taxes due based upon the net increase in value.
  • The first day of the month following ownership change or completion of new construction. The date is used to prorate the tax for the period remaining in the current fiscal year for which the bill was issued.

The bill may be paid in two installments and provides payment stubs for each installment, which show the amount due and the date that the amount must be paid to avoid penalties for late payment.

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8) What if I purchase a piece of property and then sell it again after a few months?

If you purchase and then sell property within a short period of time, the supplemental tax bill you receive should cover only those months during which you owned the property, and the new owner should receive a separate supplemental tax bill. Because of the large number of parcels and frequency of property changing hands in Sonoma County, there are often delays in placing new assessments on the roll. Be sure to check the dates used to prorate the bill to ensure that the period covered is the period during which you actually owned the property. If you receive an incorrect tax bill, contact the Assessor's Office at (707) 565-1888.

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9) When I purchase property or complete construction at some point during the fiscal year, will I be taxed on the supplemental value for the entire fiscal year?

No. You are only taxed on the supplemental value for the portion of the current fiscal year remaining after you purchased the property or completed new construction.

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10) So, it's possible to get more than one supplemental tax bill?

Yes. It is possible to receive several supplemental tax bills, depending on when the ownership change or completion or new construction occurred and when the Assessor recorded the new value on the tax roll. Because property is assessed each January 1 for the upcoming fiscal year (July 1 - June 30), you will receive one supplemental bill if the change in property value due to ownership change or new construction is recorded on the tax roll between June 1 and December 31; you will receive two supplemental bills if the change in property value is recorded on the tax roll between January 1 and May 31.

Figure 1 illustrates the homeowner's obligation to pay both supplemental and annual tax bills after purchasing property or completing new construction. (NOTE: The diagram assumes an increase in property value.)

Figure 1

[PDF iconView Figure 1 diagram.]

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11) When do supplemental tax bills have to be paid?

The date on which supplemental bills become delinquent varies depending upon when they are mailed by the Tax Collector. As outlined in Figure 2 below, if the bill is mailed between July 1 and October 30, the taxes become delinquent at 5 p.m. on December 10 for the first installment and 5 p.m. on April 10 for the second installment (the same delinquency schedule as for annual tax bills mailed in November).

Figure 2
Bill mailed between 1st installment delinquent 2nd installment delinquent
July 1 and October 30 December 10 April 10

If the bill is mailed between November 1 and June 30, the delinquency dates -- which are printed on the bill -- are determined as follows: The first installment is delinquent at 5 p.m. on the last day of the month following the month the bill was mailed; the second installment is delinquent at 5 p.m. on the last day of the fourth month after the first installment delinquency date (see Figure 3).

Figure 3
Bill mailed between 1st installment delinquent 2nd installment delinquent
November 1 and June 30 Last day of the month following the month bill was mailed Last day of the 4th month after the 1st installment became delinquent

Penalties of 10% are added to any installment that is not paid on time, and an additional $20 charge is added to a late second installment.

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12) If payment of the supplemental tax bill is not made before the delinquency date because of a misunderstanding between my lender and myself, may I have the penalties excused?

No. State law stipulates that this is not an acceptable reason for excusing penalties.

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13) What happens if I fail to pay my supplemental tax bill?

The same rules apply as for unpaid annual tax bills. If your supplemental tax bill is not paid by June 30, after the second installment becomes delinquent, the property becomes tax defaulted (even if you have paid your annual tax bill). At the end of the fifth year of delinquency the property becomes subject to the power of sale. See our information on delinquent property taxes.

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14) Can delinquent supplemental taxes be paid on an installment plan?

Yes. Delinquent supplemental taxes can be paid on an installment plan in the same manner as your annual property taxes. See our information on delinquent property taxes.

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15) Am I entitled to a homeowner's exemption on my supplemental tax bill?

You may very well be eligible for a homeowner's exemption on your supplemental tax bill. Exemptions, however, are not granted automatically. You must apply to the Assessor before the 30th day following the date of the notice from the Assessor of your supplemental assessment. As long as the home you purchased did not receive the homeowner's exemption on the current year's assessment, and as long as you occupy the home as your principal residence within 90 days of the purchase date, you would be allowed the full amount ($7,000) on the supplemental assessment. If your newly purchased home did receive the full homeowner's exemption, however, you would not be able to receive the exemption on your supplemental assessment.

Example:

On May 29, 2006 you purchase a home on which no homeowner's exemption had been allowed. Because you are reassessed on the first day of the month following an ownership change, in the current fiscal year you will pay supplemental taxes for the one remaining month. Your 2005-06 supplemental assessment amounts to $20,000. If you file for and qualify for a homeowner's exemption, the entire $7,000 exemption amount would be deducted from the supplemental assessment BEFORE the taxes are calculated as follows:

  Supplemental Assessment Value subtract Homeowner's Exemption multiplied by Tax Rate multiplied by Proration Factor for June equals Tax Due
With Exemption $20,000 - $7,000 X .011 X .08 = $11.44
Without Exemption $20,000 - $0 X .011 X .08 = $17.60

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16) Are other exemptions and assistance programs available that will help defray the amount of supplemental taxes due?

Yes. Supplemental taxes are eligible for the same property tax exemptions and assistance programs as your annual taxes. In addition to the homeowner's exemption, you can apply through the Assessor's Office for a number of other assessment exemptions (e.g., veteran's, church, and welfare) that result in savings. You must, however, file for all exemptions before the 30th day following the date of the notice from the Assessor of your supplemental assessment. For further information, contact the Assessor's Office at (707) 565-1888.

In addition, the State of California administers programs that provide property tax assistance and postponement of property taxes to qualified homeowners and renters who are 62 and older, blind, or disabled. For information on the State's Homeowner or Renter Assistance Program, call the California Franchise Tax Board at (800) 868-4171. For information on the Property Tax Postponement Program, call the California State Controller's Office at (800) 952-5661. If you would like to receive additional information on understanding property taxes, delinquent property taxes, or mobilehome property taxes, please write to the Sonoma County Tax Collector, P.O. Box 3879, Santa Rosa, CA 95402, ATTN: Secured Property. You may also email your request to taxcollector@sonoma-county.org.

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17) What happens if I fail to pay my taxes on time?

If you do not pay the first installment of your annual tax bill at the Tax Collector's Office by 5 p.m. on December 10, (If December 10 falls on a weekend or holiday, taxes are not delinquent until 5 p.m. the next business day.), or payment is not postmarked by that time and date, then the taxes become delinquent and a 10% delinquent penalty is added to any unpaid balance. If you fail to pay the second installment at the Tax Collector's Office by 5 p.m. on April 10, (If April 10 falls on a weekend or holiday, taxes are not delinquent until 5 p.m. the next business day.), or payment is not postmarked by that time and date, it becomes delinquent and a 10% penalty plus an administrative charge of $20.00 is added to the unpaid balance. If you pay your second installment without having paid the first, your payment will be applied to the unpaid taxes and penalties on the first installment and will leave your second installment unpaid and possibly delinquent. If you fail to pay either or both installments at the Tax Collector's Office by 5 p.m. on June 30, (If June 30 falls on a weekend or holiday, taxes must be paid by 5 p.m. on the preceding business day.), or payment is not postmarked by that time and date, then the property becomes tax defaulted and additional penalties and costs accrue. See our section on delinquent property taxes for full information.

If you fail to pay the installments of your supplemental tax bill by the applicable delinquency dates, the same penalties accrue as for delinquent annual taxes.

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