Registration requirement: GST registration framework mandates PAN-based eligibility and Unique Identity Numbers for special entities. Every person liable must apply for registration within prescribed timeframes, with casual and non-resident taxable persons requiring earlier application; supplies from territorial waters necessitate registration at the State of the nearest baseline. Single registration is standard, separate registrations may be granted for multiple business verticals, and multiple registrations render each registration a distinct person. Voluntary registration is permitted. Applicants must have a Permanent Account Number (with specified exceptions), non-resident registration may rely on other prescribed documents, and the proper officer may register defaulters. Special entities may be granted a Unique Identity Number. Issuance, verification, certificate form, timelines and deemed grant on expiry are prescribed.