72 Pa. Stat. § 5671
The collector of taxes, collector of delinquent taxes, constable, or delinquent tax collector, or other official authorized to collect delinquent taxes under the provisions of existing general or special legislation, during the period in which he is authorized to collect the delinquent taxes of any county, city, except a city of the first class, and of any borough, incorporated district, township, poor district or school district, shall have the power, at the request of any taxpayer, to accept payment in installments of delinquent taxes or water-rents or rates, both before and after the filing of liens therefor, but he shall not be obliged to accept any installment of less than ten per centum (10%) of the face amount of the tax, water-rent or rate when it became delinquent. The acceptance of any installment or installments by any delinquent tax collector shall not prejudice the city, county, borough, incorporated district, township, poor district or school district in the collection of any balance due, or in any way impair the validity of any lien filed for such delinquent taxes, water-rents or rates, or any balance due thereon, according to the provisions of any act of Assembly applicable thereto, nor shall any penalty be abated or diminished because of the acceptance of any such installment or installments, but interest on the amount of any installment shall cease after the month in which such installment is paid.
72 P.S. § 5671