(1)Where a person has already been assessed for the total income of any tax year by way of regular assessment and the Assessing Officer is of the opinion that such person is liable to pay advance tax, he may require such person to pay advance tax on the specified sum, calculated in the manner laid down in section 405, by an order in writing, specifying the instalment or instalments in which such tax is to be paid, on or before the due date of each instalment specified in section 408.
