Oregon Revised Statutes Insurance § 742.224

(a) That the insurer may cancel the policy at any time by giving 10 days' written notice of cancellation to the insured in the event of nonpayment of premium or 30 days' written notice for any other reason. However, when fire insurance coverage is part of a package policy including commercial liability insurance, cancellation of the policy is governed by the provisions of ORS 742.702.

(b) That cancellation by the insurer may be made with or without tender of the excess of paid premium above the pro rata premium for the expired time, and that the excess, if not tendered with the cancellation, will be refunded on demand.