Taxpayers need to submit the duly complete ITR-1 Form by 31st July of the assessment year to file taxes for the previous year. For example, if the income was earned anytime between April 2015 and March 2016, then the assessment year for the same would be 2016-17. The ITR-1 Form needs to be submitted on or before 31st July 2016 in this case.
In case the taxpayer fails to complete the tax within these timelines, he/she can file a “Belated Return” any time before 31st March, 2017. However, he/she will be liable to pay interest due to the delay.