E-Invoicing Under GST: Mandatory Thresholds & Common Errors

Current Turnover Threshold

As of August 2023, e-invoicing under GST is mandatory for all registered taxpayers whose aggregate turnover exceeds ₹5 crore in any preceding financial year. This threshold has been progressively lowered from ₹500 crore (October 2020) to ₹100 crore, ₹50 crore, ₹20 crore, ₹10 crore, and finally ₹5 crore. Businesses crossing the ₹5 crore threshold must implement e-invoicing from the first of the following month.

Who Is Exempt from E-Invoicing?

Certain categories remain exempt regardless of turnover: banking/insurance/financial institutions, GTA (Goods Transport Agency) operations, passenger transport, multiplex cinema operators, and SEZ units issuing invoices to DTA. Exporters are not exempt — e-invoicing applies to exports and SEZ supplies from non-SEZ units.

• Banks, NBFCs, insurance companies
• Goods Transport Agency (GTA)
• Passenger transport service providers
• Cinema tickets under multiplex services
• SEZ units (for supplies within SEZ)

Most Common E-Invoice Errors

Based on our experience handling GST audits, these are the errors most likely to trigger scrutiny or mismatch in GSTR-2B reconciliation:

• Wrong GSTIN of buyer — leads to ITC credit mismatch
• Incorrect HSN/SAC code — triggers rate-level discrepancy
• Invoice number format not matching series declared in GSTR-1
• Missing IRN (Invoice Reference Number) on printed invoices
• Cancellation of e-invoice after 24 hours without following amendment process
• Bulk upload files with wrong JSON structure rejected by IRP

Consequences of Non-Compliance

Failure to generate e-invoices where mandatory results in the invoice being treated as invalid. The buyer cannot claim ITC on such invoices, and the seller is liable to a penalty of ₹10,000 per invoice under Section 122 of the CGST Act. Additionally, GSTR-1 auto-population from IRP only occurs for valid e-invoices, so non-compliance creates cascading reconciliation issues.