Explanation
For GST: companies and LLPs must use a DSC to file GSTR-1, GSTR-3B, and registration forms. Individuals and firms can use EVC (OTP-based) or DSC. For income tax: companies and audited entities must file ITR using DSC; individuals and most others can use EVC. DSC is a Class 3 certificate with a validity of 1 or 2 years — must be renewed before expiry. DSC is issued by authorised bodies: eMudhra, NSDL (e-Mudhra), NIC, Sify, etc. DSC is assigned to the director/partner who is authorised to sign returns (as per board resolution/LLP agreement). A CA should remind clients 30 days before DSC expiry. Verify on the respective portal before filing.