Legal Requirement under Service Tax and GST

• Digital signature was not mandatory under Service Tax for all taxpayers.
  
• It became essential for certain categories, especially for companies.
  
• Under GST, digital signatures gained legal significance for authentication.
  
• Section 2(94) of the CGST Act defines “digital signature” aligned with IT Act, 2000.
  
• The law enabled use of DSC, e-signature, or Aadhaar authentication depending on user type.
  

Mandatory Use for Specific Taxpayers

• Companies and LLPs were required to file GST returns using digital signature certificates (DSC).
  
• Government departments and PSUs also followed this rule under statutory mandates.
  
• Casual taxable persons and non-residents were exempt from mandatory DSC.
  
• Other entities could use e-signature or Aadhaar OTP as an alternative.
  
• The requirement ensured the identity and authenticity of return filers.
  

Types of Returns Covered by DSC Requirement

• Monthly and quarterly returns such as GSTR-1, GSTR-3B were included.
  
• Annual return forms like GSTR-9 also required DSC for companies.
  
• Refund applications and letter of undertakings needed DSC validation.
  
• Amendments and corrections in returns triggered authentication needs.
  
• Filing through GST portal enabled DSC-based encryption for critical forms.
  

Technological and Security Compliance

• Class II or Class III digital signature certificates were used by taxpayers.
  
• The DSC had to be registered on the GST portal before filing.
  
• DSCs provided secure logins, encrypted submissions, and non-repudiation.
  
• Token-based certificates linked to PAN ensured legal recognition.
  
• The infrastructure followed guidelines of the Controller of Certifying Authorities (CCA).
  

Flexibility and Exemptions for Small Taxpayers

• Proprietorships and partnership firms had the option to use Aadhaar OTP.
  
• Filing through facilitation centers permitted manual signature alternatives.
  
• MSMEs with limited turnover were given relaxed DSC compliance norms.
  
• Users were advised to verify requirements based on entity category.
  
• Overall framework ensured balance between security and ease of compliance.