72 Pa. Stat. § 6185
Hereafter every person, whether principal or agent, entering into, beginning, or desiring to begin, a transient retail business in any city, borough, or township of this Commonwealth for the sale of any goods, wares, or merchandise whatsoever, and who hires, leases, occupies, or uses any room, apartment, store, shop, building, railway car, or other place or structure for the exhibition and sale of such goods, wares, or merchandise, shall take out a license for the same from the proper authorities of the said city, borough, or township: Provided, however, That nothing herein contained shall apply to farmers selling their own produce, or to any sale of goods, wares, or merchandise donated by the owners thereof, the proceeds whereof are to be applied to any charitable or philanthropic purpose.
72 P.S. § 6185