Now, almost all the taxpayers are required to file their income tax return online. Here is a detailed compilation as to

1. Who are required to file income tax return electronically and who can file it manually?
2. Whether DSC is compulsory or optional in ITR?

 E-FILING 

Taxpayers fulfilling the following criteria have to file their return through e-filing mode only:

1. Individual/HUF filing ITR 1/ ITR 4 (other than an individual of the age of 80 years or more at any time during the previous year) having a refund claim in the return or having total income of more than Rs. 5,00,000 is required to furnish the return of income electronically with or without digital signature or by using electronic verification code or by signing ITR V.
   In other words super senior citizens and individual & HUF having total income not more than Rs 5 lacs can file their return either manually or electronically, only if they are filing ITR 1or ITR 4.
2. Every company shall furnish the return of income electronically under digital signature. In other words, for corporate taxpayer e-filing with digital signature is mandatory.
3. A firm or an individual or a Hindu Undivided Family (HUF) whose books of account are required to be audited under section 44ABshall furnish the return of income electronically under digital signature. In other words, in such a case, e-filing with digital signature is mandatory.
4. A resident assessee having any assets (including financial interest in any entity) located outside India or signing authority in any account located outside India shall furnish the return of income electronically with or without digital signature or by using electronic verification code.
5. Taxpayers claiming any relief u/s 90, 90A or 91 have to furnish the return of income electronically with or without digital signature or by using electronic verification code.
6. A person who is required to file ITR – 5shall file the same electronically with or without digital signature. However, a firm liable to get its accounts audited under section 44AB shall furnish the return electronically under digital signature.
7. A taxpayer who is required to furnish a report of audit under sections 10(23C)(iv), 10(23C)(v), 10(23C)(vi), 10(23C)(via), 10A, 10AA, 12A(1)(b), 44AB, 44DA, 50B, 80-IA, 80-IB, 80-IC, 80-ID, 80JJAA, 80LA, 92E, 115JB or 115VW or shall furnish the report electronically on or before the date of filing the return.
8. Return Form ITR- 3is to furnish electronically in the following modes:
   (i) by furnishing the return electronically under digital signature;
   (ii) by transmitting the data in the return electronically under electronic verification code;
   (iii) by transmitting the data in the return electronically and thereafter submitting the verification of the return in Return Form ITR-V
9. Return Form ITR-4is to be furnish electronically in the following modes:
   (i) by furnishing the return electronically under digital signature;
   (ii) by transmitting the data in the return electronically under electronic verification code;
   (iii) by transmitting the data in the return electronically and thereafter submitting the verification of the return in Return Form ITR-V
   However, where the books of accounts are required to be audited under section 44AB, the return is required to be furnished in the manner provided at (i) i.e. e-filing with digital signature.
10. Return Form ITR – 7 is to be furnished electronically in the following modes :
    (i) by furnishing the return electronically under digital signature;
    (ii) by transmitting the data in the return electronically under electronic verification code;
    (iii) by transmitting the data in the return electronically and thereafter submitting the verification of the return in Return Form ITR-V;
    (iv) Political party shall compulsorily furnish the return in the manner mentioned at (i) above where the Return Form is furnished in the manner mentioned above without digital signature, assessees have to take the print out of Form ITR-V. One copy of ITR-V, duly signed by the assessee, has to be sent by ordinary post to Post Bag No. 1, Electronic City Office, Bangalore-560100 (Karnataka).  Alternatively, the return can be verified by EVC (Electronic verification code).

PHYSICAL FILING:

1. Very Senior Citizens of the age of 80 years or more at any time during the previous year.
2. Individual/HUF filing ITR 1/ ITR 4 not having a refund claim in the return & total income is not more than Rs. 5,00,000

In short, super senior citizens and individual & HUF having total income not more than Rs 5 lacs are allowed to their income tax return manually.