(1) Introduction. The department is charged with levying the state taxes authorized by law. As part of this task, the department apportions the amount of tax levied for state purposes among the counties in proportion to the value of taxable property in each county for the year to ensure that each county pays its due and just share of the state tax. This rule explains how the state property tax levy rate is determined, how the department adjusts the previous year's apportionment because of changes and errors in taxable values reported to the department after October 1 of the preceding year, and how the limit factor set forth in RCW 84.55.010 is applied to the state levy.

(2) Calculation of state levy rate. The levy rate for the state property tax levy is the lesser of:

(a) $3.60 per thousand dollars of the true and fair value of the taxable property in the state; or

(b) The rate that, when applied to the valuation figures specified in subsection (3) of this rule, will produce a total amount equal to the levy limit set forth in RCW 84.55.010. This levy limit equals the limit factor multiplied by the highest state property tax levy of the most recent three annual state levies, plus an amount calculated by multiplying the state levy rate for the preceding year by the increase in assessed value in the state resulting from:

(i) New construction;

(ii) Improvements to property;

(iii) Increases in the assessed value of state assessed property; and

(iv) Increases in assessed value due to the construction of wind turbine, solar, biomass, and geothermal facilities, if such facilities generate electricity and the property is not included elsewhere under chapter 84.55 RCW for purposes of providing an additional dollar amount. The property may be classified as real or personal property.

(3) Apportionment between the counties - Adjustment for changes or errors. When determining the amount of the state levy using the calculations set forth in subsection (2)(b) of this rule, the dollar amount apportioned to each county is based upon the valuation figures reported to the department by each county by October 1 of the levy year. If use of the counties' certified assessed values for state levy purposes causes an erroneous apportionment among the counties because of later changes or later-identified errors in valuation within a county, the department will adjust the following year's levy apportionment to reflect these changes and corrections.

(a) For purposes of this rule, a change in taxable value includes any final adjustment made by a reviewing body (county board of equalization, state board of tax appeals, or court of competent jurisdiction) and may also include additions of omitted property, other additions to or deletions from the assessment or tax rolls, any assessment return submitted by a county to the department subsequent to December 1st, or a change in the indicated ratio of a county.

(b) Errors requiring adjustments under this rule include errors corrected by a final reviewing body or any other error that may have come to the department's attention and would otherwise be a subject for correction in the exercise of its supervisory powers.

(4) Changes or errors in current levy - Adjust apportionment for the following year's levy. If there are any changes or errors relating to the values used in apportioning the current levy, the apportionment for the following year's levy will be adjusted. For purposes of this apportionment, the department will recalculate the previous year's levy and the apportionment thereof to correct any changes or errors in taxable values reported to the department after October 1 of the preceding year. The department will adjust the apportioned amount of the current year's state levy for each county by the difference between the dollar amounts of state levy due from each county as shown by the original and revised levy computations for the previous year.

(5) County required to correct any error upon discovery. Nothing in this rule relieves a county from its obligation to correct any error immediately upon discovery when the correction may be timely made to avoid distortion in the true apportionment of the state levy between counties.