Registration liability under GST: suppliers exceeding specified turnover thresholds must register; special category States attract a lower threshold. Liability to register arises where a supplier's aggregate turnover in a financial year exceeds the statutory threshold, with a lower threshold for supplies from special category States. Persons already registered under earlier law must be registered from the appointed day. Where a business is transferred as a going concern the transferee or successor must register from the date of transfer; for amalgamation or demerger effected by court or tribunal order the transferee must register from the date the Registrar of Companies issues the certificate of incorporation. Aggregate turnover includes supplies on own account or on behalf of principals; supplies by a registered job worker after job work completion are treated as supplies by the principal.