Pennsylvania Statutes Title 72 P.S. Taxation and Fiscal Affairs § 8209. Exemptions from tax

(a) No tax imposed by this article shall be levied upon the possession or sale of cigarettes which this Commonwealth is prohibited from taxing under the Constitution or statutes of the United States.  In addition, when the seller and purchaser have registered with the department and have obtained exemption certificates in accordance with such regulations as the department shall prescribe, the following sales are exempt:

(b) The department may otherwise promulgate regulations to relieve manufacturers and dealers from payment of tax on cigarettes sold and delivered to points inside and outside the Commonwealth for sale and use outside the Commonwealth or sold to purchasers designated as exempt by the provisions of this section.  However, all sales shall be presumed to be taxable and the burden shall be upon the person claiming an exemption to prove his right thereto.