Section 7A(7)(ii) in The Companies (Profits) Surtax Act, 1964
(ii)the advance surtax payable by it on the current chargeable amount calculated in the manner laid down in sub-section (3), and shall pay such amount of advance surtax as accords with its estimate in equal instalments on such of the dates applicable in its case under sub-section (4) as have not expired, or in one sum if only the last of such dates has not expired.