Interest  payable by assessee.
215. [(1)  Where, in any financial year, an assessee has paid [advance tax under section  209A or section  212 on the basis of his own estimate (including  revised estimate)], and the advance tax so paid is less than seventy-five per  cent of the assessed tax, simple interest at the rate of [fifteen] per cent per  annum from the 1st day of April next following the said financial year up to the  date of the regular assessment shall be payable by the assessee upon the amount  by which the advance tax so paid falls short of the assessed tax :]
[Provided that  in the case of an assessee, being a company, the provisions of this sub-section  shall have effect as if for the words "seventy-five per cent", the  words "eighty-three and one-third per cent" had been substituted.]
[(2)  Where before the date of completion of a regular assessment, tax is paid by the  assessee under section  140A or otherwise,-
            (i)  interest shall  be calculated in accordance with the foregoing provision up to the date on which  the tax is so paid ; and
           (ii)  thereafter,  interest shall be calculated at the rate aforesaid on the amount by which the  tax as so paid (in so far as it relates to income subject to advance tax) falls  short of the assessed tax.]
[(3)  Where as a result of an order under section  147 or section  154 or section  155 or section  250 or section  254 or section  260 or section  262 or section  263 or section  264 [or an order of the Settlement Commission under  sub-section (4) of section  245D], the amount on which interest was payable under sub-section (1)  has been increased or reduced, as the case may be, the interest shall be  increased or reduced accordingly, and-
            (i)   in a case where the interest is increased, the [Assessing] Officer shall serve  on the assessee, a notice of demand in the prescribed form specifying the sum  payable, and such notice of demand shall be deemed to be a notice under section  156 and the provisions of this Act shall apply  accordingly ;
           (ii)  in a  case where the interest is reduced, the excess interest paid, if any, shall be  refunded.]
(4)  In such cases and under such circumstances as may be prescribed, the [Assessing]  Officer may reduce or waive the interest payable by the  assessee under this section.
[(5)  In this section and sections  217 and 273,  "assessed tax" means the tax determined on the basis of the regular  assessment (reduced by the amount of tax deductible in accordance with the  provisions of sections  192 to 194, section  194A [, section  194C] [, section  194D] [, section  195 and section  196A] so far as such tax relates to income subject to advance tax and  so far as it is not due to variations in the rates of tax made by the Finance  Act enacted for the year for which the regular assessment is made.]
 
[(6)  Where, in relation to an assessment year, an assessment is made for the first  time under section  147, the assessment so made shall be regarded as a regular assessment  for the purposes of this section and sections  216, 217 and 273.]