72 Pa. Stat. § 5020-514.1
When the commissioners acting as a board of revision or the board for the assessment and revision of taxes, as the case may be, shall make any change in the amount of three hundred dollars ($300) or more in the assessed value of property as finally fixed in the preceding assessment roll, or shall fix the valuation of property which has not theretofore been separately fixed, whether such change or new valuation is made before or after an appeal has been heard by the board or by the court of common pleas, the board shall give notice of such change or new valuation to the clerk of the city (if it has accepted the provisions of this act) in which the assessed property is located, to the secretary of the school district in which the assessed property is located, and to the secretary of the borough or township in which the assessed property is located. The time limit within which the city, borough, township and school district is entitled to appeal from the actions of the board or from the decision of the court of common pleas shall commence to run on the day such notice is mailed or otherwise delivered.
72 P.S. § 5020-514.1