A Class 3 Digital Signature Certificate (DSC) is the electronic signature most Indian government portals expect from a business. Directors sign MCA forms with it, companies and LLPs verify GST filings with it, companies sign income-tax returns with it, and bidders sign e-tenders with it. Since the Controller of Certifying Authorities (CCA) stopped allowing standalone Class 2 individual certificates, Class 3 is effectively the only class you can buy for these uses, and it covers what Class 2 used to.
Below: where you will actually need one, which type to ask for, and how issuance works. If you would rather have the application handled, our DSC application assistance takes you through the Certifying Authority’s verification.
Where a business uses a Class 3 DSC
| Portal | Typical use | Who needs the DSC |
|---|---|---|
| MCA (company and LLP filings) | Incorporation forms, annual returns, financial statements, director and charge filings | Directors, designated partners, and the professional certifying the form |
| GST portal | Registration applications, amendments, returns, refunds | Mandatory for companies and LLPs; others can usually use EVC |
| Income-tax e-filing | Signing returns and forms | Mandatory for companies and for persons whose accounts must be audited; optional for others |
| Government e-tenders | Enrolling on the procurement portal, signing and submitting bids | The authorised signatory of the bidder |
| GeM | Some bids or bid documents may ask for digital signing | Check the specific bid’s instructions |
| DGFT | Online applications are signed digitally | Check the signing method offered on the portal |
A few points behind the table:
- MCA. Forms on the MCA portal are signed with the DSC of the director or designated partner, and the DSC must first be associated with their user profile. A new company’s first directors need DSCs before incorporation.
- GST. On the GST portal, companies and LLPs verify applications and returns with a DSC; proprietors and most other taxpayers can use an Aadhaar-based or other EVC instead.
- Income tax. On the e-filing portal, returns of companies, and of taxpayers whose accounts are required to be audited, are signed with a DSC registered on the portal. With the Income-tax Act, 2025 in force from 1 April 2026, check the current return instructions for your category.
- E-tenders. Procurement portals such as the Central Public Procurement Portal require bidders to enrol a valid DSC with their account. Tender documents usually specify a Class 3 certificate with signing usage, and some also ask for an encryption certificate.
Signing certificate, encryption certificate, or both?
- Signing certificate: proves who signed a document or form and that it has not been altered. This is what MCA, GST and income-tax filings use. Most businesses need only this.
- Encryption certificate: used to encrypt documents so only the intended recipient can open them. Some e-tender systems use it to keep bids sealed until opening.
- Combo (signing plus encryption): useful if you bid on tenders that ask for encryption.
Under the CCA’s Identity Verification Guidelines, the Certifying Authority keeps an escrow copy of the encryption key, so you can retrieve it later, even after the certificate expires, after a video verification. The escrow is retained for at least seven years after expiry. Signing keys are not escrowed.
The USB token
The guidelines require a Class 3 individual signing certificate to be issued against a private key generated on a hardware cryptographic token validated to FIPS 140-2 level 2 or 3: the familiar USB token. The DSC is the certificate; the token is where its private key lives and from which it cannot be copied out. Practical consequences:
- Keep the token and its PIN with the person whose DSC it is. A director’s DSC used by staff without control is a governance risk.
- If you forget the PIN, the guidelines provide for re-initialising the token and re-issuing the certificate for its remaining validity, rather than recovering the old key.
- Install the token driver and the portal’s signing utility on the computer you file from. Most “DSC not working” problems are driver or utility problems, not certificate problems.
How a Class 3 DSC is issued now
Issuance is entirely online with a CCA-licensed Certifying Authority (the list of licensed CAs is on the CCA website). The guidelines set out the steps:
- eKYC account. You first create an eKYC account with the CA. It is mandatory, and it is valid for up to two years; after that, a fresh verification is needed.
- Identity verification by one of the permitted routes: Aadhaar online eKYC (OTP or biometric), Aadhaar offline eKYC, PAN-based eKYC, banking eKYC, or organisational KYC for certificates issued to a person as an authorised signatory of an organisation.
- Video verification by the CA where the route requires it, along with checks of the uploaded documents against the originals.
- Key generation and download onto your token, after mobile and email OTP checks.
Choose a personal certificate for a director’s own filings, and an organisational certificate when the certificate should show the person as signing on behalf of a named organisation, for example as an authorised signatory for tenders.
Validity and renewal
Every DSC carries a fixed validity chosen when it is issued; the expiry date is shown on the certificate. After expiry, signatures can no longer be made with it, and you apply for a new certificate (going through eKYC again if your eKYC account has also lapsed). Note the expiry dates for all directors in one place; an expired DSC is a common reason for a missed MCA or GST deadline. When a new DSC is issued, register it again on each portal where the old one was registered.
Frequently asked questions
Can one DSC be used on all portals?
Yes, a Class 3 signing certificate can be registered on MCA, GST, income tax and procurement portals. Each portal needs it registered separately against your account there.
Can a company hold a DSC in its own name?
DSCs are issued to individuals. An organisational certificate is still issued to a person, showing the organisation they sign for.
Is Aadhaar e-sign the same as a DSC?
No. Aadhaar-based e-sign is a one-time electronic signature without a token, accepted on some portals for some filings. Where a portal asks for a DSC, e-sign does not substitute for it.
Complianto (complianto.in), operated by Mentorcorp Private Limited, is a private consultancy and is not affiliated with any government body. We do not issue official documents. We charge a professional fee for application assistance and advisory services. Applicants can apply directly to the government without our fees via the official portals: MCA (mca.gov.in), Income Tax (incometax.gov.in), GST (gst.gov.in), MSME (udyamregistration.gov.in), FSSAI (foscos.fssai.gov.in), Startup India (startupindia.gov.in), and IP India (ipindia.gov.in).
This article is general information, not legal or tax advice.
