Corporations that are required to apportion income between Oregon and other states, are required to use either the current period's actual or the prior full year's apportionment factor to meet the annualization exception to underpayment of estimated taxes. The prior year's apportionment factor may only be used if the prior year's return covered a full 12 months and the Oregon apportionment factor was greater than zero.
Or. Admin. Code § 150-314-0319
Stat. Auth.: ORS 305.100
Stats. Implemented: ORS 314.525