GST e-invoicing
Issuing tax invoices under India's GST rules, with the right tax split for each sale and, where required, registering them with the government system for an IRN and QR code.
Updated October 2026 · with examples from our own builds
What does GST e-invoicing mean in practice?
Every GST invoice has to carry the right tax treatment: broadly, CGST plus SGST for a supply within a state, IGST across states, zero-rated for exports and none when the seller isn't registered. Businesses above the government's turnover threshold must also register invoices on the e-invoice system, which returns an Invoice Reference Number and a QR code, often through a GST Suvidha Provider.
Getting this wrong creates work for your customers' accountants and for you. Rules such as pure-agent reimbursements billed without GST, or TDS deducted by the customer, belong in the design rather than in a later fix.
Many products keep e-invoice registration outside at first: export the invoice, register it and record the IRN back. That is a reasonable first step if it is written down.
GST e-invoicing at a glance
- Tax split
- CGST plus SGST within a state, IGST across states
- E-invoice output
- An IRN and QR code from the government system
- Common route
- A GST Suvidha Provider (GSP) adapter
Where has GST e-invoicing come up in our builds?
The proposal gives invoices, credit notes and debit notes their IRN, QR code and e-way bill through a GSP adapter that logs every call and retries failures, bills pure-agent reimbursements without GST beside taxable service charges, and records receipts as gross, TDS and net. Proposed, not built.
GST is one module: the two parties' states decide CGST plus SGST or IGST per line, in paise, with the round-off as its own line. Legal e-invoicing stays outside: the invoice is exported and the IRN and QR are typed back in.
The tax branch follows the seller's registration and the buyer's location: no GST when the seller isn't registered, a zero-rated export for foreign buyers, CGST plus SGST within the state and IGST across states.
Common questions about GST e-invoicing
Does my product need to generate e-invoices from day one?
Only if your business, or the businesses using your product, fall under the e-invoicing mandate. Even then, exporting invoices and recording the IRN back is a workable first step, as the Firetrix design does.
Who decides whether a sale carries CGST and SGST or IGST?
The rules do, based on the supplier's location and the place of supply, not the staff member raising the invoice. The system should work it out from the parties' details rather than leave someone to pick.
Related terms
Sources
Planning a product and not sure where GST e-invoicing fits? Ask us, or browse all 116 terms in the glossary.