(a) To any person as to whom it is beyond the legal power of a school district imposing a tax under this act to impose the tax herein provided for under the Constitution of the United States and the Constitution and laws of the Commonwealth of Pennsylvania.

(b) To institutions or organizations operated for public, religious, educational or charitable purposes, to institutions or organizations not organized or operated for private profit, or to trusts and foundations established for any of the said purposes.

(c) To any person as to whom, or privilege, transaction, subject, occupation or property as to which, cities of the second class are without authority to tax under the provisions of the act of June 25, 1947 (P.L. 1145), as now or hereafter amended.¹

This section shall not be construed to exempt any person who is an employer from the duty of collecting the tax at source from his employes and paying the amount collected to the treasurer under the provisions of section 4 of this act.²