Section 15. The Commission shall have power, after hearing, upon notice, by order in writing to require every public utility:

(a) To comply with the laws of the Philippine Islands and with any provincial resolution or municipal ordinance relating thereto and to conform to the duties imposed upon it thereby or by the provisions of its own charter, whether obtained under any general or special law of the Philippine Islands.

(b) To furnish safe, adequate, and proper service as regards the manner of furnishing the same as well as the maintenance of the necessary material and equipment Provided, however, That the inspection and regulation, for the purposes of sanitation and safety, of the vessels operated within the Philippine Islands, shall be under the jurisdiction and authority of the Insular Collector of Customs or his duly authorized agents.

(c) To establish, construct, maintain, and operate any reasonable extension of its existing facilities, where, in the judgment of said Commission, such extension is reasonable and practicable and will furnish sufficient business to justify the construction and maintenance of the same, and when the financial condition of the said public utility reasonably warrants the original expenditure required in making and operating such extension.

(d) To keep its books, records, and accounts so as to afford an intelligent understanding of the conduct of its business and to that end to require every such public utility of the same class to adopt a uniform system of accounting. Such system shall conform to any system approved and confirmed by the Auditor for the Philippine Islands.

(e) To make specific answers with regard to any point on which the Commission requires information, and to furnish annual reports of finances and operations. Such reports shall set forth in detail the capital stock issued, the amounts of said capital stock paid up and the form of payment thereof; the dividends paid, the surplus, if any, and the number of stockholders; the consolidated and pending obligations, and the interest paid thereon; the cost and value of the property of the carrier, concessions or franchises and-equipments; the number of employees and salaries paid to each class; the accidents to passengers, employees, and other persons, and the causes thereof; the annual expenditures on improvements, the manner of their investment and nature of such improvements; the receipts and profits in each of the branches of the business and of whatever source; the operating and other expenses; the balance of profits and losses; and a complete statement of the annual financial operations of the carrier, including an annual balance sheet. Such reports shall also contain any information which the Commission may require concerning freight and passenger rates, or agreements, compromises or contracts affecting the same. Said reports shall cover a period of twelve months, ending on December thirty-first of each year, and shall be sworn to by the officer or functionary of the public utility authorized therefor.

(f) To carry, whenever, in the judgment of the Commission, it may reasonably be required, for the protection of stockholders, bondholders, or creditors, a proper and adequate depreciation account in accordance with such rules, regulations, and forms of account as the Commission may prescribe. The Commission shall from time to time ascertain and determine, and by order in writing, after hearing, fix proper and adequate rates of depreciation of the property of each public utility, in accordance with such regulations or classifications, which rates shall be sufficient to provide the amounts required over and above the expense of maintenance to keep such property in a state of efficiency corresponding to the progress of the industry. Each public utility shall conform its depreciation accounts to the rates so ascertained, determined, and fixed, and shall set aside the moneys so provided for out of earning and carry the same in a depreciation fund. The income from investments of moneys in such fund shall likewise be carried in such fund. This fund shall not be expended otherwise than for depreciation, improvements, new constructions, extensions or additions to the property of such public utility.

(g) To give such notice to the Commission as the Commission may, by rule, require of any and all accidents which may occur within the Philippine Islands upon the property of any public utility as herein defined or directly or indirectly arising from or connected with its maintenance or operation, and to investigate any such accident and to make such order or recommendation with respect thereto as in its judgment may be just and reasonable.

(h) When any public utility as herein defined proposes to increase or reduce any existing individual rates, joint rates, tolls, charges, or schedules thereof, as well as commutation, mileage, and other special rates, or change or alter any existing classification, it shall send written notice thereof to the Public Utility Commission thirty days prior to the date on which the proposed increase, reduction, change or alteration is to take effect, unless the Commission, by means of an order, consent to a shorter notice, and upon receipt of said notice, the Commission shall be authorized, either upon complaint in writing or by virtue of its office, to see and determine whether said increase, reduction, change or alteration is just and reasonable. The burden of proof to show that the said increase, reduction, change or alteration is just and reasonable shall lie upon the public utility making the same. The Commission shall have power pending such hearing and determination to order the suspension of the said increase, reduction, change or alteration until the said Commission shall have approved said increase, reduction, change or alteration, not exceeding three months.

(i) No public utility as herein defined shall operate in the Philippine Islands without having first secured from the Commission a certificate, which shall be known as Certificate of Public Convenience, to the effect that the operation of said public utility and the authorization to do business will promote the public interests in a proper and suitable manner. Every public utility existing on the date of the approval of this Act shall pay the fees herein prescribed for the issuance of the proper certificate of public convenience or public necessity and convenience, as the case may be, in the same manner as said fees shall be payable by any new public utility subject to the provisions of this Act, within sixty days from the date of the approval of this Act: Provided, however, That in the case of a public utility for the operation of whose business it is necessary to obtain a franchise from either a municipal government, or a provincial government, under the provisions of Act Numbered Six hundred and sixty-seven, as amended by Act Numbered Ten hundred and twenty-two, or from the Philippine Legislature, such public utility shall secure a certificate to be known as Certificate of Public Necessity and Convenience, as required by section twenty-two of this Act. The duty to secure such certificates of public convenience or certificates of public necessity and convenience by public utilities or to pay the fees herein prescribed by public utilities already existing is of a mandatory character and noncompliance herewith may, in the judgment of the Public Utility Commission, be sufficient ground for the revocation and cancellation of any vested right and for the imposition of the penalty provided for in this Act.