72 Pa. Stat. § 5567.3
In case any taxpayer shall default in the payment of any instalment of taxes or in the payment of current taxes, as required in section one of this act, the penalties and interest or penalties, as the case may be, on the instalments of such delinquent taxes remaining shall not be abated, but shall remain due and payable as provided by existing law.
At any time during the instalment period, any taxpayer may pay the entire amount of or the balance due on delinquent taxes, whereupon penalties, interest, and all costs on delinquent taxes for the year one thousand nine hundred and thirty-three and prior years, and penalties and all costs on delinquent taxes for the year one thousand nine hundred and thirty-four, shall be abated, and all liens, filed for delinquent taxes, satisfied of record: Provided, however, Taxes for the then current year and all prior years are paid.
72 P.S. § 5567.3