The short answer

**Disclaimer:** This article is for informational purposes only and does not constitute legal, tax or compliance advice. Laws change frequently. Always consult a qualified GST professional before implementing changes. On 1 June 2026, the GST e-invoicing regime expanded to cover composition-scheme dealers for business-to-business (B2B) supplies—a material shift from earlier phases that exempted them.

Suppliers with annual turnover exceeding 5 crore rupees must now generate and report e-invoices through the Goods and Services Tax Network (GSTN) for all B2B invoices, effective immediately. This marks the third phase of mandatory e-invoicing rollout and affects thousands of manufacturers, traders and service providers operating under composition. The requirement applies regardless of buyer category.

Market signals

Composition dealers now mandated for B2B e-invoicing

Previously exempt from e-invoicing, composition-scheme suppliers with turnover above 5 crore are now required to issue e-invoices for all business-to-business supplies. This removes the earlier distinction between composition and regular taxpayers in the B2B context, raising compliance complexity for smaller composition dealers.

GSTN system updates and API readiness

GSTN has issued technical specifications for composition-dealer e-invoice generation, including revised JSON schemas and validation rules. Many legacy invoicing systems require API integration updates; SMEs must audit their ERP and accounting software for Phase 3 compatibility within the next 30–45 days.

ITC impact and audit trail tightening

E-invoices now create immutable digital audit trails, raising scrutiny on ITC claims. Buyers will see granular line-item and HSN-level data; any mismatch between composition-dealer invoices and buyer records may trigger notice-based reconciliation or demand letters.

◆ What it means for you — the Vinayakam view

Under the Central Goods and Services Tax Act, 2017, composition taxpayers were previously allowed to issue paper invoices without e-invoicing; Phase 3 eliminates this exemption for B2B supplies. The Ministry of Finance (Department of Revenue) and GSTN have published detailed guidelines on supplier identification, invoice structure and return mapping. Non-compliance—including failure to e-invoice or late e-invoice filing—may invite GST demand notices, penalties and interest under sections 122–129 of the CGST Act. Vinayakam Consultants advises composition-scheme businesses to conduct immediate system readiness audits, review vendor invoicing workflows, and engage GST consultants to map e-invoice data to existing returns (Form GSTR-1 and GSTR-4) to avoid reconciliation gaps and departmental action.

Your action checklist

  • Confirm your composition-scheme turnover threshold (above 5 crore in preceding FY) and verify whether Phase 3 e-invoicing applies; obtain written confirmation from your GST advisor or use GSTN's eligibility checker.
  • Audit your invoicing software and ERP system for Phase 3 e-invoice API compatibility; request vendor certification or plan integration within 30 days; test invoice generation and GSTN upload in sandbox mode.
  • Map all existing B2B customer records (GSTIN, PAN, address) into your e-invoicing system; flag any incomplete or outdated customer data that may cause invoice rejection or ITC mismatches at buyer end.
  • Review your Form GSTR-4 (quarterly composition return) submission process to ensure e-invoice line-item details (HSN, quantity, rate, tax value) align with return declarations; engage a GST consultant to validate reconciliation before 30 June 2026.

Frequently asked questions

When does GST e-invoicing Phase 3 for composition dealers start?

GST e-invoicing Phase 3 for composition-scheme dealers becomes mandatory on 1 June 2026 for all B2B supplies. Composition dealers with annual turnover exceeding 5 crore rupees must generate and report e-invoices through GSTN.

Which composition dealers must comply with Phase 3 e-invoicing?

Composition-scheme suppliers with annual turnover exceeding 5 crore rupees must now e-invoice all B2B supplies, regardless of buyer category. Previously, composition dealers were exempt from e-invoicing mandates.

How should SMEs prepare for GST e-invoicing Phase 3?

SMEs should audit their ERP and accounting software for Phase 3 compatibility within 30–45 days and update API integrations with GSTN systems. Review revised JSON schemas and validation rules issued by GSTN for composition-dealer e-invoice generation.

GST e-invoicingcomposition schemecompliance deadlineB2B invoicing
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