Article 51 mandates Corporate Tax registration for all Taxable Persons with the Federal Tax Authority (FTA). The FTA prescribes the form, manner, and timeline for registration to obtain a Tax Registration Number. The Authority may also require certain Exempt Persons, as listed in Article 4, and Unincorporated Partnerships to register. It grants the FTA discretionary power to register a Person based on available information if they fail to comply with this obligation. Such a registration would be effective from the date the Person first became a Taxable Person, ensuring comprehensive compliance with the law's provisions from inception.