Registration requirement: taxable persons must apply within prescribed time; failure allows officer-initiated registration after verification. Every person liable must apply for registration within thirty days (casual or non-resident at least five days prior). Single registration is granted, with separate registrations allowed for distinct business verticals. Voluntary registration is permitted and attracts registered-person obligations. Multiple registrations or establishments in different States are treated as distinct persons. Eligibility requires a Permanent Account Number (or Tax Deduction and Collection Account Number where applicable); non-residents may use prescribed alternative documents. The proper officer may register non-compliant persons. Special notified persons may receive a Unique Identity Number. Grant or rejection follows prescribed verification within the prescribed period, and registration is deemed granted if no deficiency is communicated.