Return of Income and Procedure of Assessment (Section 139 to 154)

Table Showing Compulsory Filing of 'Return of Income' by various Persons with Sectionwise (Section 139)
Various "Return Forms" for filing Return of Income
Mode of "Submission of Income-Tax Return" for the Assessment year 2019-20 is as follows–
Due Date or Time for Filing Return of Income [Section 139(1)]

ITR-1 (SAHAJ) Return Form
ITR-2 Return Form
ITR- 4 (SUGAM) Return Form
ITR- 5 Return Form
ITR- 6 Return Form
Manner of Furnishing Return of Income by a Person with Specified Conditions [Rule 12(3)]
Preparation of IT Return by Authorised Representative [Rule 12A]:

Conditions to Furnish a Revised Return of Income under Section 139(5)
'Completion of Assessment' in reference to Section 139(5):
Can a Return Filed under section 139(3) or 139(4A) or 139(4B) or 139(4C) or 139(4D) be Revised:
Can a Return Filed within the time extended by CBDT be Revised:
Can a Return Furnished in response to Notice under Section 142(1) be Revised:
Can Revised Return be further Revised:
Revised Return substitutes the Original Return:
Can a Return be Revised after receipt of Notice under Section 143(2) / Show cause notice under section 144:

What is a Defective or Incomplete Return
When a Return of Income is Defective ?
Defective or Incomplete Return of Income due to Annextures , Statements , Accounts etc.

Varification of Return U/s 139 in the case of an 'Individual' —
Varification of Return U/s 139 in the case of a 'Hindu Undivided Family (HUF)'—
Varification of Return U/s 139 in the case of a 'Company' —
Varification of Return U/s 139 in the case of a 'Firm' —
Varification of Return U/s 139 in the case of a 'Limited Liability Partnership (LLP)'—
Varification of Return U/s 139 in the case of a 'Local Authority (LA)'—
Varification of Return U/s 139 in the case of a 'Political Party (PP)'—
Varification of Return U/s 139 in the case of 'Any Other Association (AOA)'—
Varification of Return U/s 139 in the case of 'Any Other Person (AOP)'—

Provisions of Section 140A of Self-Assessment
Procedure for Self-Assessment and Determination of Tax Liability of Self-Assessment :
1. Tax Liability of Self-Assessment
2. Procedure of Self-Assessment Tax of Return

Section 142 and 142A deals with the following :

1. Giving notice to the assessee to submit return (if not submitted earlier), produce accounts, documents, etc.	Section 142(1)
2. Making inquiry and giving opportunity to assessee	Section 142(2), (3)
3. Giving direction to get books of account audited	Section 142(2A) to (2D)
4. Estimates by Valuation Officer in certain cases for Assessment of Tax	Section 142A
5. Consequences of Non-compliance of Section 142(1) and Section 142(2A)

Adjustement of Income or Loss submitted by Assessee by Assessing Officer Under Section 143(1)
Opportunity to the Assessee by the Assessing Officer under Section 143(1)
Intimation to the Assessee by the Assessing Officer under Section 143(1)
Scheme for Centralized Processing of Return [Section 143(1B)]:
Processing of Return within the prescribed Time and enable withholding of Refund in certain cases [Section 143(1D)] [W.r.e.f. 2017-18]

Compulsory Service of Notice to the Assessee for Scrutiny Assessment [Section 143(2)]
Selection of Cases for Scrutiny Assessment :
Purpose of Scrutiny Assessment
Procedure for Scrutiny Assessment
Prescribed Authority for Scrutiny Assessment under Section 143(2) [Rule 12E].—
Notice deemed to be valid in certain circumstances for Scrutiny Assessment [Section 292BB]:
Consequences of Failure to comply with Notice for Scrutiny Assessment under section 143(2):
Assessment after Evidence [Section 143(3)]

When can Reassessment Process be started for any Income Escaping Assessment [Proviso 3 to Section 147]-
Deemed Cases of Income Escaped Assessment (Explanation 2 of Section 147)
Issue of Notice for Income Escaping Assessment under Section 148

Rectification only when mistake apparent from the record and by the authority who passed the order [Section 154(1)]:
When can Rectification be made [Section 154(2)]:
Rectification can be done for any matter other than the matter considered and decided in Appeal / Revision [Section 154(1A)]:
Opportunity of being heard is necessary if Rectification results into Enhancement, etc. [Section 154(3)]:
Order of Rectification [Section 154(4)]:
Refund to be given in case Rectification results into Reduction of Assessment [Section 154(5)]:
Notice of Demand to be issued in case Rectification results in to Enhancing the Assessment, etc. [Section 154(6)]:
Time limit for Rectification [Section 154(7)]:
Time Limit for Passing an Order of Rectification if Application for Amendment made by the Assessee under Section 154 [Section 154(8)]:
Rectification of Order which is subject to Appeal or Revision
Initiation of Rectification by whom
The Procedure to be followed for making an Application of Rectification
MCQ on Rectification of Mistake under Section 154