72 Pa. Stat. § 4841
That the board of revision of taxes or the commissioners of every county in this Commonwealth shall annually furnish the assessors of the several townships, boroughs, and cities of the respective counties, with blanks to be prepared by them; and it shall be the duty of each of said assessors to furnish a copy of the same to every taxable person, copartnership, unincorporated association, joint-stock association and company, limited partnership and corporation, in his respective ward, district, borough, or township, or to any officer, agent or employe found at the place of business of any such limited partnership or corporation in his ward, district, borough, or township; upon which blank each taxable person, copartnership, unincorporated association, company, limited partnership, joint stock association, and corporation shall, respectively, make return annually of the aggregate amount of all the different classes of personal property made taxable by the first section of this act, held, owned, or possessed by said person, copartnership, unincorporated association, company, limited partnership, joint-stock association, or corporation, either in his, her, or its own right, or as trustee, agent, attorney-in-fact, or in any other capacity, for the use, benefit or advantage of any other person, persons, copartnership, unincorporated association, company, limited partnership, joint-stock association, or corporation; which return shall be made and certified to by such taxable person, and, in the case of copartnerships, unincorporated associations, and joint-stock associations and companies, by some member thereof, and, in the case of limited partnerships and corporations, by the president, chairman or treasurer thereof: Provided, That any corporation, joint-stock association, or limited partnership, doing business in more than one county, shall be liable to make such return only in the county in which its principal office within this Commonwealth is situated, except where two or more banks or banking institutions or trust companies shall have been consolidated; a report as to all trust funds taxable under this act held by any of the said individual companies prior to the consolidation shall be made and the tax paid in the county wherein such individual company was located prior to the consolidation. And except where any bank, banking institution or trust company has established a branch in a different county, a report shall be made of all trust funds, taxable under this act, held by the branch, or turned over to the main bank, banking institution or trust company, or acquired by reason of a trust created at the branch, and the tax paid in the county wherein the branch is located, and shall not be taxable in any other county: And provided further, That whenever any personal property taxable under the provisions of this act was owned by a decedent at the time of his death and is held by his executor or administrator, return of such personal property shall be made and the tax paid in the county wherein such decedent was domiciled at the time of his death, notwithstanding the residence or location of such executor or administrator or of any beneficiary, or the place where such securities are kept: And provided further, That whenever any personal property taxable under the provisions of this act is held, owned, or possessed as trustee, agent, attorney-in-fact, or in any other manner as hereinabove set forth, by two or more persons, copartnerships, unincorporated associations, companies, limited partnerships, joint-stock associations, or corporations, all of which are residents of the Commonwealth, but not all of which are domiciled in the same county, return of such personal property shall be made in each county of this Commonwealth where any of the same are domiciled, and there shall be paid in each such county that portion of the tax imposed upon such personal property so held, owned, or possessed, as the number of such trustees, agents, or attorneys-in-fact domiciled therein bears to the total number thereof, notwithstanding the residence of any beneficiary or the place where such personal property is kept.
72 P.S. § 4841