53 Pa. C.S. § 8848
(a) Notice requirements.--If any county proposes to institute a countywide revision of assessments upon real property, the following notice requirements shall apply:
(1) Each property owner shall be notified by mail at the property owner's last known address of the value of the new assessment, the value of the old assessment and the right to appeal within 40 days as provided in subsection (c)(1). The notice shall state a mailing date and shall be deposited in the United States mail on that date. The notice shall be deemed received by the property owner on the date deposited in the United States mail.
(2) The chief assessor shall maintain a list of all notices and the mailing dates for each and shall affix an affidavit attesting to the mailing dates of the assessment notices. This list shall be a permanent public record of the county assessment office and available for public inspection.
(b) Informal review.--In conjunction with a countywide revision of assessments, a designee of the county assessment office may meet with property owners to review all proposed assessments and correct errors prior to the completion of the final assessment roll. In no event shall the market value or assessed value of a property be adjusted as a result of an informal review except to reflect changes to tabular data or property characteristics inaccurately recorded during the revision. Informal reviews, if conducted, shall be completed no later than June 1.
(c) Appeal process.--
(1) All property owners and affected taxing districts shall have the right to appeal any new assessment value within 40 days of the mailing date stated on the notice.
(2) The county assessment office shall mail all notices on or before July 1. The board in its discretion may commence with the hearing of appeals 40 days following the mailing of the initial notices of reassessment.
(3) The county assessment office shall notify each appellant, property owner, if not the appellant, and each affected taxing district of the time and place of hearing on the appeal by mailing a notice no later than 20 days prior to the scheduled hearing date. Any appellant who fails to appear for hearing at the time fixed shall be conclusively presumed to have abandoned the appeal unless the hearing date is rescheduled by the mutual consent of the appellant and the board.
(4) On or before November 15, the county assessment office shall certify to the taxing districts new assessment rolls resulting from the countywide revision of assessments.
(5) All appeals shall be heard and acted upon by the board not later than October 31.
(d) Common level ratio.--If a county has effected a countywide revision of the assessments, which was used to develop the common level ratio last determined by the State Tax Equalization Board, the following shall apply:
(1) If a county changes its assessment base by applying a change in predetermined ratio, the board shall apply the percentage change between the existing predetermined ratio and newly established predetermined ratio to the county's common level ratio to establish the certified revised common level ratio for the year in which the assessment was revised.
(2) If the county performs a countywide revision of assessments by revaluing the properties and applying an established predetermined ratio, the board shall utilize the established predetermined ratio instead of the common level ratio for the year in which the assessment was revised and until the time that the common level ratio determined by the State Tax Equalization Board reflects the revaluing of properties resulting from the revision of assessments.
53 Pa.C.S. § 8848