Every tax payer is required to declare to the Income tax Department in the Government of India, at the end of a financial year, in a form prescribed by the Government, summary of incomes which he earned during the year ended on 31st March.
While it is true that one might have paid all due tax on his salary earnings, it is possible and highly probable that he has other incomes like interest on savings bank, dividends from companies, cash incomes from part time work or other varied sources like rent, fees, royalties on which no tax has been deducted or, if deducted, only on a portion/part.
The Government collects this statement in the form of a Tax Return in one of the eight forms prescribed.
This statement duly signed and affirmed by the individual as it being a complete and true statement of his income during the previous financial year is called RETURN OF INCOME. (Income Tax Return).
Eligibility to fill ITR:
If a person(exclude senior citizen)salary is 2.5 lakh/annum than he has to fill it to the Indian government.