72 Pa. Stat. § 5020-516
The county commissioners, or the board for the assessment and revision of taxes, of the several counties shall, except in counties of the second class, on or before the first day of December of each year, at the expense of the county, furnish to the township commissioners of each township of the first class, and to the township supervisors of each township of the second class and to borough councils, for their use, a properly certified duplicate of the last adjusted valuation of all real estate, personal property, and occupations made taxable for county purposes in such townships or boroughs. Such duplicate shall state the name of each taxable, with the valuation, description, and kind of property and occupation of such taxable. The duplicate may be corrected, amended or changed after the first day of December as circumstances may require.
72 P.S. § 5020-516