Income Tax | Filing Returns - Why Four ITR Forms for Individuals / HUF?

The 4 forms are designed on a hierarchical order and the forms should be referred as below. The 'Assessee' with lower form relevance should not go for higher one.

Case #	Income from Salaries and Interest under head “Other Sources”	Any income other than “Partnership”, and/or “Proprietorship”	Income from Partnership in business	Income from Proprietorship business	ITR Form
Case 1.	Yes	X	X	X	ITR - 1
Case 2.	Yes / No	Yes	X	X	ITR - 2
Case 3.	Yes / No	Yes / No	Yes	X	ITR - 3
Case 4.	Yes / No	Yes / No	Yes / No	Yes	ITR - 4

Sr.#	Sources/Details of Income	Individual	Individual, HUF
		ITR-1	ITR-2	ITR-3	ITR-4	ITR-4S
1	Income from Salary/Pension	Yes	Yes	Yes	Yes	X
2	Income from Other Sources (only Interest Income or Family Pension)	Yes	Yes	Yes	Yes	X
3	Income/Loss from Other Sources	X	Yes	Yes	Yes	X
4	Income/Loss from House Property	X	Yes	Yes	Yes	X
5	Capital Gains/Loss on sale of investments/property	X	Yes	Yes	Yes	X
6	Partner in a Partnership Firm	X	X	Yes	Yes	X
7	Income from Proprietary Business/Profession	X	X	X	Yes	X
8	Income from Presumptive Business	X	X	X	X	Yes
9	Details of Foreign Assets	X	Yes	Yes	Yes	X

Sr.#	Details	ITR Form No.
1	For Firms, AOPs and BOIs	ITR 5
2	For Companies, other than companies claiming exemption under section 11	ITR 6
3	For person required to furnish return under section 139(4A)/ (4B) / (4C)/ (4D)	ITR 7