Complete guide to India GST e-invoicing compliance requirements, IRN generation, QR code rules, and IRP integration.
India introduced mandatory e-invoicing under the GST regime in October 2020. The system requires businesses above specified turnover thresholds to generate electronic invoices through the Invoice Registration Portal operated by the Goods and Services Tax Network.
Every invoice must be uploaded to the IRP to receive a unique Invoice Reference Number and digitally signed QR code. The IRN and QR code must appear on all B2B invoices. This enables real-time data flow to GST systems and prevents invoice fraud.
The mandate has progressively expanded to cover businesses with turnover above 10 crore rupees as of April 2023. Compliance is mandatory for all B2B invoices but excludes B2C retail transactions.
Businesses with aggregate turnover exceeding 500 crore rupees in any financial year from 2017-18 onwards.
Expanded to businesses with turnover above 100 crore rupees.
Further expanded to businesses with turnover above 50 crore rupees.
Expanded to businesses with turnover above 20 crore rupees.
Expanded to businesses with turnover above 10 crore rupees. This is the current threshold as of 2026.
The Invoice Reference Number is a unique 64-character alphanumeric hash generated by the IRP when an invoice is successfully registered. The IRN is derived from the supplier GSTIN, invoice number, financial year, and document type.
Businesses must integrate with GSTN IRP portals either directly via API or through GST Suvidha Providers. The invoice data must be submitted in JSON format conforming to the GSTN schema. The IRP validates the invoice, generates the IRN, digitally signs the invoice, and returns a QR code.
The signed invoice with IRN and QR code must be shared with the buyer. The IRN cannot be modified after generation. If an invoice needs correction, the original must be cancelled and a new invoice issued.
IRN generation must occur before the invoice is dispatched to the customer. Invoices without valid IRNs are not compliant and can result in penalties.
Every e-invoice must display a digitally signed QR code provided by the IRP. The QR code embeds key invoice data including supplier GSTIN, invoice number, invoice date, taxable value, and IRN hash.
The QR code enables buyers and tax authorities to verify invoice authenticity by scanning. It also prevents tampering since the digital signature will break if any embedded data is altered.
The QR code must be printed on the physical invoice copy and must remain readable when scanned by standard QR reader applications. Minimum size requirements apply to ensure readability.
Occurs when the same invoice number, supplier GSTIN, and financial year combination has already been registered. Use unique invoice numbers and avoid reusing numbers across financial years.
Ensure supplier and buyer GSTINs are valid 15-character alphanumeric codes. Validate format before submission to avoid rejection.
For businesses with turnover above 5 crore, 6-digit HSN codes are mandatory. Below 5 crore, 4-digit codes are acceptable. Ensure correct HSN code length based on turnover.
Invoice date cannot be in the future or more than 7 days in the past. Ensure system clocks are synchronized and generate IRNs within the permissible date window.