California Code of Regulations
Title 18 - Public Revenues
Division 1 - State Board of Equalization-Property Tax (California Department of Tax and Fee Administration - Timber Yield Tax, See Chapter 11)
Chapter 2 - Assessment
Article 6 - Local Roll
Section 255 - Enrollment of Supplemental Assessments

(a) When the period for claiming exemption has expired, and any exemptions have been processed, the assessor shall transmit the supplemental assessment and the following information to the auditor:

(b) The auditor shall apply the current year's tax rate, as defined in Section 75.4 of the Revenue and Taxation Code, to the supplemental assessment or assessments, computing the amount of taxes that would be due for a full year. If the tax rate for the "roll being prepared" is known, the rate may be used with respect to the fiscal year to which it applies, rather than the current year's tax rate as defined in Section 75.4. If the tax rate for the "roll being prepared" is not known, the current year's tax rate as defined in Section 75.4 shall be used. For property on the supplemental roll, the taxes due shall be computed in two equal installments.

(c) The taxes due shall be adjusted by a proration factor as set forth in Section 75.41 of the Revenue and Taxation Code to reflect the portion of the tax year remaining as determined by the date on which the change in ownership occurred or the new construction was completed. In computing the portion of the tax year remaining, the change in ownership or completion of new construction shall be presumed to have occurred on the first day of the month following the date on which change in ownership or completion of new construction occurred.

(d) After computing the supplemental taxes due, if the total is twenty dollars ($20) or less, the auditor may cancel the amount as provided by Section 4986.8 of the Revenue and Taxation Code.

(e) If the supplemental assessment is a negative amount, the auditor shall follow the procedures of section 75.41 of the Revenue and Taxation Code to determine the amount of refund to which the assessee may be entitled.

(f) No supplemental assessment authorized by this regulation shall be valid, or have any force or effect, unless it is placed on the supplemental roll on or before the applicable date specified in Revenue and Taxation Code section 75.11.

(g) No limitations period specified in Revenue and Taxation Code section 75.11 shall commence unless the filing or transmittal specified in the relevant paragraph has been completed.

(h) If, before the expiration of the applicable period specified in subdivision (f) for making a supplemental assessment, the taxpayer and the assessor agree in writing to extend the period for making a supplemental assessment, correction, or claim for refund, a supplemental assessment may be made at any time prior to the expiration of that extended period. The extended period may be further extended by successive written agreements entered into prior to the expiration of the most recent extension.