GST registration: timelines, PAN requirement and unique identity number rules govern eligibility, verification and deemed grant. Every person liable to registration must apply in the prescribed manner and period; casual and non-resident taxable persons must apply before commencing business. Single registration is the norm, with separate registrations allowed for distinct business verticals. Voluntary registration is permitted and attracts all registered-person obligations. Multiple registrations or establishments are treated as distinct persons. Registration eligibility requires a Permanent Account Number, with alternative Tax Deduction and Collection Account Number or other prescribed documents for certain persons. The proper officer may register defaulters, while notified international entities may receive a Unique Identity Number. Applications undergo prescribed verification, may be deemed granted if no deficiency is communicated within the verification period, and a certificate is issued in prescribed form.