1. Interest u/s 234A: If there is tax due after deducting advance tax, TDS and self assessment tax then interest will be applicable @1% per month and part thereof up to the date of filing of the return besides interest applicable u/s 234B or 234C. Means this interest is applicable only if there is any tax payable in your return.
2. Loss of Interest on refund: You may loose interest on refund u/s 244A as delay in filing is attributable to assessee for the period by which you have filed late return.
3. Audit Report: Person who are liable to get their accounts audited should get the audit report on or before the due date of filing return i.e 30.09.2013. E filing of audit report s mandatory from A.Y. 2013-14.
4. Revised return: Late/belated return can not be revised. This is major draw back. If you failed to file return in time then you cannot revise your income tax return. Though you may apply revision u/s154 but it has few limitation and very lengthy process.
5. Some of deduction under subsection 80 are not available for late return.
6. Due date of income tax return is related to TDS deposit and dis allowance u/s 40a(ia).
7. Due date of Income Tax return is related to tax saving u/s 54,54B,54F and some other issues in capital gain saving account deposit scheme.
8. Not able to carry forward the losses under various heads: You are not able to carry forward following type of losses if file return after due date:-
- Speculation loss.
- Business loss excluding loss due to un absorbed depreciation and capital exp on scientific research.
- Short term capital loss.
- Long term capital loss.
- Loss due to owning and maint. of horse races.