(a) Amounts lawfully imposed retroactively by order of another governmental agency; or

(b) Amounts deferred under subsection (2) of this section.

(2) Upon application of a telecommunications utility or ratepayer or upon the commission’s own motion and after public notice and opportunity for comment, the commission by order may authorize deferral, for later incorporation in rates, telecommunications utility expenses or revenues, the recovery or refund of which the commission finds should be deferred in order to minimize the frequency of rate changes or the fluctuation of rate levels or to match appropriately the costs borne by and benefits received by ratepayers. The authority under this subsection is limited to the following accounts:

(a) Increases or decreases in amounts incurred by a telecommunications utility resulting from changes in jurisdictional separations approved by the Federal Communications Commission;

(b) Increases or decreases in amounts incurred by a telecommunications utility resulting from changes in depreciation rates or amortization schedules approved by the commission;

(c) Increases or decreases in amounts incurred by a telecommunications utility resulting from changes in income, excise, franchise or ad valorem taxes by the federal, state or local governments;

(d) Increases or decreases in amounts incurred by a telecommunications utility resulting from restoration of telecommunications services interrupted by floods, fires, earthquakes, storms or other acts of nature;

(e) Increases or decreases in amounts incurred by a telecommunications utility for research, development, planning and advance advertising for products and services not yet in service;

(f) Increases or decreases in amounts incurred by a telecommunications utility for telephone plant transfers and property sales approved by the commission;

(g) Increases or decreases in amounts incurred by a telecommunications utility from affiliated interest contracts and transactions approved by the commission;

(h) Increases or decreases in amounts incurred by a telecommunications utility from attorney’s fees, court settlements and court awards;

(i) Increases or decreases in amounts incurred by a telecommunications utility resulting from changes in accounting methods approved by the commission; and

(j) Increases or decreases in amounts incurred by a telecommunications utility from customer service contracts, intercompany service contracts and joint and through service arrangements.

(3) The commission may authorize deferrals under subsection (2) of this section beginning with the date of application, together with interest established by the commission. A deferral may be authorized for a period not to exceed 12 months beginning on or after the date of application.

(4) Unless subject to an automatic adjustment clause under ORS 759.180, amounts described in this section shall be allowed in rates only to the extent authorized by the commission in a proceeding to change rates and upon review of the utility’s earnings at the time of application to amortize the deferral.

(5) In any one year, the overall average rate impact of the amortizations authorized under this section shall not exceed three percent of the telecommunications utility’s gross revenues for the preceding calendar year.

(6) The provisions of this section may be used as a means of deferring the effect of readily identifiable and readily measurable changes in particular costs or revenues of a telecommunications utility, but shall not be used to implement a claim for an increase or decrease in the overall revenue requirement of a telecommunications utility when the amount of the change or changes would not be known until the completion of a rate case. [1989 c.929 §2]