16 Pa. Stat. § 1774
The county commissioners together with the county treasurer and the county controller in second class A counties shall have authority to designate any bank, savings bank, bank and trust company, trust company or national banking association located within the county as a deputy county tax collector, for the sole purpose of receiving and receipting for county taxes paid to the deputy county tax collector at the collector's place of business. The county tax collector shall not be held responsible for losses occasioned by the failure of any institution, for money received by it as a deputy. Each institution acting as a deputy county tax collector shall, within five days after the last day of each calendar month, transmit to the county tax collector all money received by it as the deputy during the preceding month. Each payment shall be accompanied by an itemized statement showing what taxes have been paid, the dates when paid and by whom they have been paid. An institution shall not be allowed any compensation or commission for acting as a deputy other than expenses actually incurred in transmitting money and records of payments to the county tax collector.
Each institution, before entering upon the duties of receiving and receipting for taxes, shall post security in an amount as determined by the commissioners together with the treasurer and the county controller, to ensure the faithful performance of duties and the payment over of all taxes and money received.
16 P.S. § 1774