The due date for filing income tax returns is 31st July,2013 except for those individuals who are engaged in business or profession and whose accounts are required to be audited as per the provisions of the Act. Individuals earning more than Rs 40 lakhs in a year in profession is required to get their accounts audited.
Last date for these individuals is 30th September. Tax returns filed after due date is considered as belated returns. You can file belated return for a particular financial year (within 2 years form the end of the relevant financial year under Section 139 (4) of the Act).
Here are the some limitations of the belated return :
Revision of tax return not possible. If there is some misstatement in the ITR then revised return cannot be filed if return has been filed after due date. When you have full taxes before due date then you could file the return after the due date without paying additional interest otherwise additional interest of 1% per month has to be paid. And if the taxes have not been paid entirely before the due date , you could end up paying additional interest on account of delay in payment of tax and subsequent delay in filing the return within the due date.