47 Pa. Stat. § 796
It shall be the duty of the board to transmit to the department on, or before, the fifteenth day of each calendar month, a statement of its receipts from sales of liquor and taxes collected during the preceding fiscal month, and such other information as may be necessary to effectuate the provisions of this act, at which time it shall also be the duty of the board to pay to the department the tax imposed upon such liquor by the provisions of this act: Provided, That the board may, in its discretion, add the tax imposed by this act to the wholesale and retail price at which liquors are sold and eliminate any accounting of such tax separate from sale prices, and in such case, the amount of the tax for any calendar month shall be ascertained by dividing the entire gross receipts derived from sales at Pennsylvania liquor stores during such month by six and five-ninths (6 5/9 ), and the quotient thus obtained shall be deemed the amount of the tax for such month payable over, under this section.
47 P.S. § 796