Registration requirement: taxable persons must apply within prescribed timelines; PAN or TAN documentary alternatives required; UIN for notified entities. Persons liable for GST must apply for registration within thirty days (casual and non resident persons five days prior), with registration generally single but separate registrations possible for business verticals. PAN is required for registration, with a Tax Deduction and Collection Account Number acceptable for deductors and alternative documents for non residents. Multiple registrations or establishments in different States are treated as distinct persons. The proper officer may register defaulters, notified international bodies may receive a Unique Identity Number, and registration is subject to prescribed verification, issuance of a certificate, and deemed grant if no deficiency is communicated.