Senate Bill 813, enacted on July 1, 1983, amended the California Revenue and Taxation Code to create what are known as Supplemental Assessments. This law requires that any increase or decrease in assessed value due to a change in ownership or completed new construction becomes effective beginning with the first day of the month following the event date rather than on the next annual tax bill. Supplemental assessments result in tax bills (or refunds) that are issued in addition to the annual property tax bill sent to property owners in October.
A supplemental tax bill is generated whenever a property is reassessed due to a change in ownership, or the completion of new construction. The supplemental tax bill (or refund) reflects any increase (or decrease) in property tax generated by the supplemental event.
The Kern County Treasurer-Tax Collector maintains a useful tool for estimating supplemental tax bills.
If your Notice of Supplemental Assessment indicates a net increase and the resulting bill exceeds $4.50, a Supplemental Tax Bill will be issued by the Treasurer-Tax Collector. Supplemental Bills are issued 45 days after the Notice of Supplemental Assessment is mailed.
If your Notice of Supplemental Assessment indicates a net decrease and the resulting refund exceeds $4.50, you will receive a supplemental refund in the form of a tax voucher. This voucher can be used to pay down the second installment of your annual property tax bill, or submitted to the Auditor-Controller for refund once both installments of the annual tax bill are paid. The Auditor will not issue a supplemental refund until both installments are paid in full.
The sale or transfer of a full or partial interest in property, including a transfer consequent to the death of a property owner, may result in a reassessment and the issuance of a supplemental bill.
Certain forms of property transfer are not subject to reassessment. Exceptions include:
For further information, please contact the Assessor's Office Title Department at (661) 868-3300, or click the following link for exclusion forms.
New construction typically involves an improvement to real property, such as a room addition, pool or garage. An alteration which restores a building to the "substantial equivalent of new" (such as a complete renovation) would also qualify as new construction. Certain types of construction, such as solar panels, are exempt from assessment, and normal repair and maintenance is not considered new construction.
Only the newly constructed portion may be reassessed. The value of the existing property is not affected.
The Assessor determines the fair market value of new construction as of the date of completion or the fair market value of the portion of property transferred as of the transfer date. Once the new value has been determined, the Assessor issues a Notice of Supplemental Assessment indicating the new assessed value and the net change in assessed value.
You have the right to appeal any assessed value if you feel that it exceeds the market value of the property in question, provided that the appeal is filed in a timely manner. Appeal of supplemental assessments must be filed with the Clerk of the Board of Supervisors within sixty (60) days of the mailing date shown on the supplemental bill or the supplemental voucher.
If you feel a supplemental assessment is incorrect, we recommend that you discuss the assessment with the Assessor’s Office as soon as possible after receiving notice and prior to filing an appeal. If you can provide the assessor with convincing evidence that the assessment was incorrect, the assessment could be corrected without an assessment appeal hearing.
Important: Filing an appeal does not relieve the applicant from the obligation to pay property taxes on or before the applicable due date shown on the tax bill.
Further information about the appeals process may be obtained by contacting the Clerk of the Board of Supervisors at (661) 868-3616.
No. Mortgage servicing agencies do not receive the supplemental tax bill. Supplemental bills are sent directly to the owner of record. Only annual tax bills mailed in October are sent to lenders.
There are three reasons why an owner may receive more than one supplemental tax bill:
1. Supplemental event occurred between January 1 and May 31
A supplemental tax bill is always generated for the remainder of the fiscal year in which the event occurred.
An event occurring between January 1 and May 31 will create a second supplemental assessment for the following fiscal year because the annual assessment roll, established at midnight January 1 for the fiscal year beginning July 1, will not reflect the change in value generated from a January to May event and must be adjusted to reflect the difference.
2. Prior owner had a supplemental event in the same fiscal year
You can also receive multiple supplemental bills in situations where a series of supplemental events take place within the same fiscal year for different owners. If the bill for the prior owner’s supplemental event is for the same fiscal year in which you took ownership, you will receive a portion of that bill, pro-rated for the time period that you owned the property.
3. Multiple supplemental events occurred while you owned the property
If multiple supplemental events (changes in ownership and new construction) occurred while you own the property, you will receive one or two supplemental bills for each of these events. Supplemental assessments are generated for each event.
Yes. The supplemental tax bill is sent in addition to the annual tax bill and both must be paid.
You may be eligible to receive the Homeowners’ Exemption of up to $7000 of assessed value on a supplemental tax bill if the property you acquired was not already receiving the exemption on the annual tax bill and the property will be your principal place of residence.
New property owners are automatically sent a Homeowners’ Exemption claim form, but the exemption is not automatically granted. To receive the full exemption, you must submit a claim to the Assessor’s Office no later than the 30th day following the date of notice. An exemption for 80% of the full amount will be granted for a late claim if the claim is filed by the due date of the first tax installment.
The Homeowners’ Exemption can only be applied to a supplemental assessment that is a net increase and results in a supplemental tax bill. It cannot be applied to a supplemental assessment lowering the value.
Yes. In addition to the Homeowners’ Exemption, eligible owners may apply for other exemptions such as the Disabled Veterans, Church, or Welfare Exemption. Applications must be received by the Assessor no later than the 30th day following the date of notice printed on the Notice of Supplemental Assessment. For further information regarding exemptions, contact the Exemptions staff at (661) 868-3265.