1. What is DSC?
Digital Signature Certificate (DSC) is the electronic format of a physical or paper certificate. It serves as a proof of identity of an individual or Organization for a certain purpose online / on computer. It authenticates an electronic document like how a handwritten signature authenticates a printed / handwritten document.

2. Why is DSC required?
e-Filing users who have opted for this facility require DSC to sign Income Tax Returns / Statutory Forms or to verify response against notices issued by Income Tax Department, for refund reissue request and for certain other purposes. To sign or verify any document, the user should have first registered their DSC with e-Filing system.  

3. What is an emsigner?
emsigner is a utility that is required for DSC registration. It has different versions suitable to different websites. For registering the DSC, a hyperlink to download and install the emsigner utility is available on the e-Filing portal.

To install the utility, click on hyperlink available under “Need Help” section at the bottom of the “Register DSC” page

 
or 

Follow Path: e-filing portal Home page >> Download >> DSC Management Utility>> Utility (emBridge)

4. When do I need to re-register my DSC?
You will need to re-register your DSC either when the present DSC has expired or if you want to update the already registered DSC.

5. Where can I procure a DSC?
A valid DSC can be procured from a certifying authority and the same must be registered on the e-Filing portal post login.

6. Is the DSC always registered against the PAN of a user?
DSC will be registered against the PAN of the Individual user except in the case of Non-Resident Director of a Foreign Company. In case of Non-Resident Director of a Foreign Company, DSC will be registered against their email ID.

7. Is DSC mandatory for certain services / users?
DSC is mandatory for some services / user categories such as e-Verification of returns filed by companies and political parties as well as other persons whose accounts are required to be audited under the Income Tax Act. In other cases, it is optional. 

8. While registering a DSC, the message 'The Digital Signature Certificate is already registered' is displayed. What should be my course of action?
A DSC cannot be registered by multiple users. The error message might mean that the DSC is already registered against another taxpayer. Ensure that the DSC belongs to you and the PAN and email ID are encrypted. However, the exception to this is, a Principal Contact may use the same DSC for both Individual and Organization for verification of returns and other purposes. For other error messages pertaining to PAN mismatch and expiry of DSC, the PAN must be checked, and a valid DSC should be registered respectively.
 

9. Whose DSC is required to be used for verification of ITRs and Statutory Forms for Non- Individual Taxpayers like Company / Firm / HUF?
Non-individual taxpayers require the DSC of the Principal Contact for Verification of ITR and statutory forms.

10. If I already have a DSC, do I need a new one for e-Filing?
If you have a Specified Class 2 or 3 DSC for any other application, the same can be used for e-Filing as long as the DSC has not expired, or has not been revoked.

11. What is a DSC PIN? Where can I get it?
DSC PIN is the password which the subscriber of the digital signature will have to use while uploading a digital signature. Every DSC token comes with a default PIN. You can choose to change the PIN through the installed DSC driver software (after you insert your DSC token into the USB port of your computer).