Single registration for CNG manufacturers enables consolidated compliance while duty and CENVAT tie to registered manufacturing premises. Single registration is authorised for CNG manufacturers for all manufacturing premises under one Chief Commissioner, with jurisdictional extension of the registering Commissioner to other units for enforcement purposes. CENVAT credit is confined to inputs and capital goods used at registered compression premises; daughter stations are excluded. Duty must be based on quantity manufactured and cleared at the registered premises, and quantities filled into mobile cascades must be measured at point of filling using suitable measuring devices, with a possible three-month lead time for installation.