Section 7C(2)(b) in The Companies (Profits) Surtax Act, 1964
(b)that any such company as is referred to in clause (b) of sub-section (5) of section 7A has not sent the estimate referred to in that clause, simple interest at the rate of [fifteen per cent] [Substituted for the word "twelve per cent" by Act 67 of 1984, section 77] per annum from the 1st day of April next following the financial year in which the advance surtax was payable in accordance with the said sub-section (5) or sub-section (6) up to the date of the regular assessment shall be payable by the company upon the amount equal to the assessed surtax.