W. Va. Code § 3-2-6

(a) Voter registration before an election closes on the 21st day before the election or on the first day thereafter which is not a Saturday, Sunday, or legal holiday at

(1) 11:59 p.m. for online registration; or

(2) At the close of business at county clerk's offices and the Secretary of State's office.

(b) An application for voter registration, transfer of registration, change of name, or change of political party affiliation submitted by an eligible voter by the close of voter registration is effective for any subsequent primary, general, or special election if the following conditions are met:

(1) The application contains the information required by §3-2-5(c) of this code. Incomplete applications for registration containing information which are submitted within the required time may be corrected within four business days after the close of registration if the applicant provides the required information; and

(2) The application is received by the appropriate clerk of the county commission no later than the hour of the close of registration or is otherwise submitted by the following deadlines:

(A) If mailed, the application shall be addressed to the appropriate clerk of the county commission and is postmarked by the postal service no later than the date of the close of registration. If the postmark is missing or illegible, the application is presumed to have been mailed no later than the close of registration if it is received by the appropriate clerk of the county commission no later than the third day following the close of registration;

(B) If accepted by a designated agency or motor vehicle licensing office, the application is received by that agency or office no later than the close of registration;

(C) If accepted through a registration outreach program, the application is received by the clerk, deputy clerk, or registrar no later than the close of registration;

(D) If accepted through an approved electronic voter registration system, the application is received by the clerk of the county commission or other entity designated by the Secretary of State no later than 11:59 p.m. on the final day of registration; and

(3) The verification notice required by the provisions of §3-2-16 of this code mailed to the voter at the residence indicated on the application is not returned as undeliverable.