Oregon Revised Statutes Revenue and Taxation § 317.660

(1)(a) If the income of an insurer is derived from business done both within and without this state, the determination of Oregon taxable income shall be arrived at by multiplying the insurer's net income by the insurance sales factor.

(b) The insurance sales factor shall consist of a fraction, the numerator of which is the amount of direct premiums (excluding reinsurance accepted and without deduction of reinsurance ceded) received or earned by the insurer during the tax year on policies and contracts that are allocated to this state and to other jurisdictions in which the insurer is not authorized to do business, and the denominator of which is the total of such premiums received or earned by the insurer during the tax year on policies and contracts that had been sold within and without this state.

(a) “Net income” means net income properly recorded in the statement of income reported in the annual statement filed by the insurer with the Director of the Department of Consumer and Business Services.

(b) “Premiums” means sums properly included in those schedules of the annual statement filed by the insurer with the Director of the Department of Consumer and Business Services that appropriately allocate premiums by jurisdiction. If the exclusion of reinsurance premiums results in an insurance sales factor that does not fairly represent the extent of the taxpayer's activity in this state, the taxpayer may petition for and the Department of Revenue may permit, or the Department of Revenue may require, the inclusion of reinsurance premiums in the insurance sales factor. If the annual statement of the insurer does not report received premiums then the insurance sales factor shall be determined based on earned premiums.

(b) The inclusion of the insurance sales factor and one or more additional factors that will fairly and equitably represent the taxpayer's business activity in this state; or

(c) The employment of any other method to achieve a fair and equitable apportionment of the taxpayer's income.