Section 18
SEC. 18. It shall be unlawful for any individual, copartnership, association, corporation or joint-stock company, their lessees, trustees, or receivers appointed by any court whatsoever, or any municipality, province, or other department of the Government of the Philippines, to engage in any public service business without having first secured from the Commission a certificate of public convenience or certificate of public convenience and necessity as provided for in this Act, except grantees of legislative franchises expressly exempting such grantee from the requirement of securing a certificate from this Commission, as well as concerns at present existing expressly exempted from the jurisdiction of the Commission, either totally or in part, by the provisions of section thirteen of this Act.