Okla. Admin. Code § 710:10-6-3
In order to obtain the exemption for a storm shelter, the applicant must be the actual owner of the property on January 1 of the year for which the exemption is sought. If evidence of title is not executed on or before January 1 and filed of record in the office of the County Clerk on or before February 1, no exemption can be allowed.
Added at 20 Ok Reg 2154, eff 6-26-03