Many people comes to me and say last date of filling income tax return(ITR) is 31st March not 31st july. Are they correct? If, yes why some people says due date of filing of ITR is 31st July? and Why income tax department organise camps for return filing in the month of july? Here is also some question arise? What is the last date of filing of ITR? What would be impact if one missed the deadline of 31st July? What is the penalty/ interest for non filing of ITR within due date? In this post I will try to clear this doubt and will tell you the penalty and interest for delays in filing of return. Friends always remember that we filed return for previous year in assesment year. Now the question is that- What is previous year and what is assesment year. Understand it with an example- Mr. X earn some income during 01/04/2013 to 31/03/2014, in this case previous year i.e PY is 2013-2014 and Assesment year i.e AY is 2014-15. Now as per section 139(1) of