Interest Chargable in Certain Cases

Section 234A. Interest for Late Filing of Return of Income
Where the return of income is furnished after the due date, or is not furnished, the assessee shall be liable to pay simple interest at the rate of 1 per cent for every month or part of a month on the amount of the tax due as per the return.

Section 234B. Interest for defaults in payment of advance tax
Where, an assessee who is liable to pay advance tax has failed to pay such tax or, where the advance tax paid by such assessee is less than ninety per cent of the assessed tax, the assessee shall be liable to pay simple interest at the rate of 1 per cent for every month or part of a month comprised in the period from the 1st day of April next following such financial year.

Section 208. Conditions of liability to pay advance tax
Advance tax shall be payable during a financial year in every case where the amount of such tax payable by the assessee during that year is five thousand rupees or more. The due dates for various instalments of advance tax are: September 15 -- amount not less than 30% of such advance tax, December 15 -- amount not less than 60% of such advance tax and March 15 -- balance amount of such advance tax.

Section 234C. Interest for Deferment of Advance Tax
For other than a company. If an assessee has failed to pay advance tax under section 208 or
(i) Advance tax paid on or before 15 September is less than 30% of tax due, on the shortfall interest is payable at 1 per cent per month for three months,
(ii) Advance tax paid on or before 15 December is less than 60% of tax due, on the shortfall interest is payable at one per cent per month for three months, and
(iii) Advance tax paid on or before 15 March is less than 100% of tax due, on the shortfall interest is payable at one per cent per month for period till the tax is paid.

Sections 201(1A) and 206C(7). Failure to Deduct or Pay Tax at Source (TDS).
If the person responsible for deducting tax at source or after deducting the tax fails to deposit the same as required, he is required to pay interest at the rate of 1 per cent for every month or part of a month comprised in the period from the date the tax was deducted to the date on which the tax was deposited with the Government. Also the quarterly TDS return can not be submitted unless the interest is paid.

Rule 119A. The amount of tax on which the interest is calculated will be rounded off to the nearest multiple of Rs. 100 ignoring any fraction of Rs. 100.