Depending on the date of change of ownership or completion of new construction, you may receive one or two supplemental bills:

• A single supplemental assessment based on the difference between the new base year value (market value) and the assessed value on the current Secured Roll (the previous owner's Prop. 13 value)

Generally, a supplemental assessment is prorated based on the number of months remaining in the fiscal year. Thus, for a December transfer, which increases the assessment value by $50,000, the supplemental assessment would be the $50,000 additional value prorated for six months (January 1 - June 30).

• The first supplemental assessment is based on the difference between the new base year value (market value) and the assessed value on the current Secured Roll
  (Prop. 13 value). This is for the remaining portion of the current fiscal year ending June 30.
• The second supplemental assessment is based on the difference between the new base year value (market value) and the assessed value to be enrolled on the Secured Roll being prepared. This will be for the new fiscal year beginning July 1.

When calculating supplemental assessments, the effective date is carried over to the first day of the month following the date of the transfer or completion of new construction.

For example, if a deed is recorded or if new construction is completed on May 15th, the date on the supplemental assessment will be June 1.

If the property purchased after lien date (January 1) has a homeowners' exemption, it will remain in effect for the remainder of the upcoming fiscal year. If the property did not have a homeowners' exemption when it was purchased, the homeowner has thirty (30) days from the mailing of the Notice of Supplemental Assessment to file a claim. To receive additional information, please call (714) 834-3821.

The Homeowner's Exemption Form is not available on-line.

Once the property changes ownership, is rented, leased, or otherwise used by the developer or owner-builder, a supplemental assessment is made. The date of completion of new construction is "conclusively presumed" to be the date the new construction is available for use by the developer or owner-builder. To request an application form or additional information, please call (714) 834-5674.

A taxpayer has sixty (60) days from the date of the mailing of the Notice of Supplemental Assessment within which to file an assessment appeal for that valuation.

Contact the Clerk of the Board of Supervisors for an assessment appeal application, or further assistance. Their telephone number is (714) 834-3453

Supplemental tax bills are due on the date mailed and become delinquent on the last day of the month following the month that the bill is mailed. Supplemental bills are payable in two installments. Bills mailed between July and October are delinquent on the same dates as regular bills on the the secured roll (December 10 and April 10).