Without prejudice to the contrary anything contained in this Act, any seller, and transferor or lesser of any goods, manufactured, produced or imported into Bangladesh or a provider of service specified in the Second Schedule, who is a person outside the scope of section 15 and sub-section (1) may, if he desires, apply, in the form and manner set by Rules, to the concerned Officer for voluntary registration as a supplier of taxable service and, the concerned Officer shall, if he is satisfied that the application is in order in all respects, register the applicant and give him a Registration Certificate mentioning therein his Business Identification Number and the person so registered shall be treated as a taxpayer under this Act and all provisions relating to tax assessment and payment under this Act shall be applicable to him.