Digital Signature for GST: When It's Mandatory and How to Register It

The GST portal supports two ways to authenticate returns — Electronic Verification Code (EVC) and Digital Signature Certificate (DSC). For companies and LLPs, DSC is mandatory. Here's how the rules break down and how to register your DSC without the signature-verification errors that plague first-time users.

When DSC is mandatory on GST

• Companies (Private Limited, Public Limited) — DSC mandatory for all filings.
• Limited Liability Partnerships (LLP) — DSC mandatory.
• Foreign companies and Foreign LLPs — DSC mandatory.
• Individuals, HUFs, partnerships and proprietorships can use EVC (OTP-based), though DSC is still recommended for volume filers.

Which DSC class works on GST?

Only Class 3 is accepted post-January 2021. Class 2 certificates issued before the cutover still work until expiry but can't be renewed. Any DSC you buy today is Class 3 by default.

Registering your DSC on the GST portal

1. Log in to the GST portal with your GSTIN.
2. Go to My Profile → Register / Update DSC.
3. Insert your USB token and select the certificate from the emSigner popup.
4. The signature validates and the DSC is now linked to your GSTIN.

Common errors and fixes

• emSigner not detected: the emSigner utility isn't running. Start it from the system tray and refresh the browser.
• Signature failed: browser has an outdated Java plugin or the token driver is stale. Update both.
• PAN mismatch: the DSC's underlying PAN doesn't match the signatory PAN on GSTIN. Fix at the source (PAN correction or new DSC).

For Bangalore GST filers, we run a signature-troubleshooting session on a screenshare — usually 15 minutes and the portal is back to accepting your submissions.