W. Va. Code § 33-6-19

Any insurance policy terminating by its terms at a specified expiration date and not otherwise renewable, may be renewed or extended at the option of the insurer and upon a currently authorized policy form and at the premium rate then required therefor for a specific additional period or periods by certificate or by endorsement of the policy, and without requiring the issuance of a new policy when such certificate and its use for such purpose have been approved by the commissioner.