Who Must Use DSC for Income Tax Filings?
DSC is mandatory for income tax filings in several specific situations. Other taxpayers may use alternative verification methods like OTP or EVC. The table below summarises when DSC is required:
| Filing Type / Entity | DSC Mandatory? | Alternative |
|---|---|---|
| ITR filed by companies (ITR-6) | ✓ Yes | None |
| ITR with Tax Audit (Sec. 44AB) | ✓ Yes | None |
| Audit report upload (3CB-3CD, 3CA-3CD) | ✓ Yes (CA's DSC) | None |
| ITR by LLPs | ✓ Yes | None |
| ITR by political parties | ✓ Yes | None |
| ITR-1, ITR-2, ITR-4 (individuals, small businesses) | Optional | Aadhaar OTP / EVC |
| Responding to IT notices | Recommended | EVC / OTP |
Important: Any individual or firm whose accounts are subject to tax audit under Section 44AB of the Income Tax Act must file returns using a DSC — OTP-based verification is not accepted.
DSC for Tax Audit Reports (Form 3CB-3CD & 3CA-3CD)
When a taxpayer's accounts are audited under Section 44AB, the Chartered Accountant conducting the audit must upload the audit report (Form 3CB-3CD or 3CA-3CD) on the Income Tax portal using their own DSC. The taxpayer must then accept the report using their DSC as well.
This means two DSCs are involved in the audit filing process:
- CA's DSC — used to upload and certify the audit report
- Taxpayer's DSC — used to accept and approve the uploaded report
If either DSC is expired or not registered, the audit report submission will fail. Ensure both DSCs are valid and registered on the IT portal before the due date (typically 30th September or 31st October depending on the year).
DSC for Company Income Tax (ITR-6)
All companies registered in India must file their Income Tax Return using Form ITR-6 and must sign it using a DSC. The DSC must be in the name of a designated director or company secretary as per the Income Tax Act.
A single DSC that is already registered for the company on MCA21 and the GST portal can also be registered on the Income Tax portal — there is no need for a separate DSC for each portal.
How to Register DSC on the Income Tax Portal
Follow these steps to register your DSC on the Income Tax e-filing portal (incometax.gov.in):
- Log in to incometax.gov.in with your PAN and password.
- Go to My Profile → Register DSC.
- Plug in your DSC USB token and install drivers if not done already.
- Select the certificate from the dropdown and enter your token PIN.
- Click Register to complete the process.
Once registered, you can use the DSC to sign and submit ITRs, upload audit reports, respond to notices, and more on the portal.
DSC vs e-Verification (OTP) — Which Should You Choose?
For individual taxpayers (salaried employees, freelancers, small businesses without audit), the Income Tax portal allows e-verification via Aadhaar OTP or Electronic Verification Code (EVC). This is convenient and free.
However, for regular filers, professionals, and businesses, a DSC is the better choice because:
- OTP expires in minutes — DSC signing is instantaneous once the token is plugged in
- No dependency on Aadhaar OTP delivery or telecom network
- DSC can be used across multiple portals (GST, MCA, IT)
- DSC is the only option when audit reports or company returns are involved