Cenvat credit transition: manufacturers opting for exemption must pay credit on stocks and remaining credit lapses on transition. A manufacturer opting for exemption based on annual clearances must pay an amount equal to the credit for inputs in stock or contained in finished goods on the effective date, with any remaining credit balance lapsing and unavailable for duty payment. A unit availing SSI exemption may switch to the Cenvat scheme after crossing the SSI limit or earlier and, upon switching, may take Cenvat credit on raw material stocks, stock in process and inputs contained in finished goods.