West Virginia Code Chapter 11. Taxation § 11-13A-9a. Periodic installment payments of tax imposed by section three of this article

(A) Each such taxpayer shall, on or before the last day of each month, make out an estimate of the tax for which the taxpayer is liable for the preceding month, sign the same and mail it together with a remittance, in the form prescribed by the tax commissioner, of the amount of tax due to the office of the tax commissioner: Provided, That the installment payment otherwise due under this paragraph on or before the thirtieth day of June each year shall be remitted to the tax commissioner on or before the fifteenth day of June, beginning the fifteenth day of June, one thousand nine hundred eighty-eight.

(B) In estimating the amount of tax due for each month, the taxpayer may deduct one twelfth of any applicable tax credits allowable for the taxable year and one twelfth of any annual exemption allowed for such year.