W. Va. Code R. § 110-15-8d
Persons who perform "contracting" as defined in W. Va. Code '11-15-2 or persons acting in an agency capacity, may not assert any exemption to which the purchaser of such contracting services or the principal is entitled. Any statutory exemption to which a taxpayer may be entitled shall be invalid unless the tangible personal property or taxable service is actually purchased by such taxpayer and is directly invoiced to and paid by such taxpayer: Provided, That this section shall not apply to purchases by an employee for his or her employer; purchases by a partner for his or her partnership; or purchases by a duly authorized officer of a corporation, or unincorporated organization, for his or her corporation or unincorporated organization so long as the purchase is invoiced to and paid by such employer, partnership, corporation or unincorporated organization.
Transition rule. - This section shall not apply to purchases of tangible personal property or taxable services in fulfillment of a purchasing agent or procurement agent contract executed and legally binding on the parties thereto prior to September 15, 1990: Provided, That this transition rule shall not apply to any purchases of tangible personal property or taxable services made under such a contract after August 31, 1991; and this transition rule shall not apply if the primary purpose of the purchasing agent or procurement agent contract was to avoid payment of consumers sales and use taxes.
W. Va. Code R. § 110-15-8d