Okla. Stat. tit. 36, § 4003

There shall be a provision that a grace period of thirty (30) days, or, at the option of the insurer, of one month of not less than thirty (30) days, shall be allowed within which the payment of any premium after the first may be made, during which period of grace the policy shall continue in full force; but if a claim arises under the policy during such period of grace before the overdue premium is paid the amount of such premium may be deducted from the policy proceeds. Laws 1957, p. 371, § 4003.