GST e-invoicing: IRN, QR & IRP workflow
From 1 August 2023, every registered taxpayer with aggregate turnover above ₹5 crore must report B2B invoices, credit notes, and debit notes to the Invoice Registration Portal (IRP) before issuing them. The IRP returns an IRN and a QR code that make the invoice legally valid for input tax credit. Here's how the system works — and how HelloBooks runs it for you.
What e-invoicing actually is
E-invoicing is not'invoicing through email' or 'PDF invoicing'. It is a standard schema (Form GST INV-01) that taxpayers submit to the GSTN's Invoice Registration Portal before handing the invoice to the buyer. The IRP validates the schema, generates a unique 64-character Invoice Reference Number (IRN), digitally signs the JSON, and embeds a QR code — and only then is the invoice considered issued.
The signed JSON also auto-populates GSTR-1 and Part A of the e-way bill, eliminating duplicate filing.
Who must generate e-invoices
| Effective from | Turnover threshold (any FY since 2017-18) |
|---|---|
| 1 October 2020 | ₹500 crore |
| 1 January 2021 | ₹100 crore |
| 1 April 2021 | ₹50 crore |
| 1 April 2022 | ₹20 crore |
| 1 October 2022 | ₹10 crore |
| 1 August 2023 | ₹5 crore (current threshold) |
Exempt categories: SEZ units (suppliers, not recipients), insurance companies, banking & financial institutions including NBFCs, GTAs providing road transport of goods, suppliers of passenger transport services, multiplex cinema-ticket suppliers, and Government departments and local authorities.
The IRN/QR lifecycle
- 1. Build: Supplier system creates invoice JSON in the GST INV-01 schema.
- 2. Submit: JSON goes to the IRP via a registered GSP (HelloBooks uses Fynamics).
- 3. Validate: IRP checks GSTIN, HSN, rates, totals, and duplicates against its master.
- 4. Sign: IRP generates the IRN (hash of supplier GSTIN + financial year + document type + document number), signs the JSON, and creates a QR.
- 5. Return: Signed JSON, IRN, and QR come back to the supplier system.
- 6. Issue: The supplier prints/shares the invoice with IRN and QR. Without these, the document is not a tax invoice.
- 7. Auto-populate: The IRP forwards the data to GSTR-1 and (if requested) the e-way bill portal.
Time limits and cancellation rules
- 30-day generation window: for taxpayers with aggregate turnover ≥ ₹100 crore from 1 November 2023; extended to ≥ ₹10 crore from 1 April 2025. The IRP rejects late submissions.
- 24-hour cancellation: a generated IRN can only be cancelled in full within 24 hours, and the invoice number cannot be reused for the same financial year.
- Beyond 24 hours: issue a credit note. The credit note itself goes through the IRP and gets its own IRN.
- No partial cancellation:the IRP doesn't accept amendments. Cancel and re-issue, or post a credit/debit note.
How HelloBooks does this
HelloBooks ships e-invoicing in the free plan. The Fynamics GSP integration is built in, so there's no separate GSP contract or per-IRN charge.
- 1
Connect HelloBooks to the IRP via the built-in GSP
In Settings → GST → E-Invoicing, click Connect. HelloBooks routes your GSTIN credentials to Fynamics, the GSTN-authorised GSP, which obtains the IRP API token. One-time setup, no manual JSON uploads.
- 2
Mark counterparties as B2B / SEZ / Export
On each customer master, set the GST registration type. The e-invoice flag turns on automatically for Registered, SEZ, and Overseas customers. B2C customers never trigger an IRN.
- 3
Create the invoice — the IRN is fetched in the background
Save the invoice. HelloBooks builds the e-invoice schema (INV-01), pushes to the IRP, receives the signed JSON, IRN, and QR, and embeds them on the printable invoice. Round-trip is typically under 2 seconds.
- 4
Print or share the invoice with QR
The PDF/print output carries the IRN, the IRP digital signature timestamp, and the QR code. Buyers scan the QR to verify authenticity. The same JSON flows into your GSTR-1 — no separate filing.
- 5
Cancel within 24 hours if the invoice is wrong
From the invoice screen, click Cancel IRN within 24 hours of generation. HelloBooks pushes the cancellation to the IRP and locks the document. Past 24 hours, issue a credit note (which itself gets a fresh IRN).
Frequently asked questions
What is e-invoicing under GST?
E-invoicing is the process of reporting B2B invoices, credit notes, and debit notes to the government's Invoice Registration Portal (IRP) before they are issued to the buyer. The IRP validates the invoice, returns an Invoice Reference Number (IRN), digitally signs the JSON, and embeds a QR code. Only after that is the invoice legally valid for ITC.
What is the current turnover threshold for e-invoicing?
From 1 August 2023, e-invoicing is mandatory for every registered person whose aggregate turnover in any financial year from 2017-18 onwards exceeded ₹5 crore. Once a taxpayer becomes liable, the obligation continues even if turnover later drops below the threshold. Exempt categories include SEZ units, banking & financial institutions, insurance, GTAs, passenger transport, multiplex cinemas, and government departments.
Which documents need an IRN?
Tax invoices, debit notes, and credit notes for B2B supplies, supplies to SEZs (with or without payment), and exports. B2C invoices do not need an IRN, but taxpayers above ₹500 crore turnover must print a self-generated dynamic QR on B2C invoices.
What is the time limit to generate an IRN?
From 1 November 2023, taxpayers with aggregate turnover of ₹100 crore or more must generate the IRN within 30 days of the invoice date. From 1 April 2025, this 30-day window also applies to taxpayers with aggregate turnover of ₹10 crore or more. Outside the window, the IRP rejects the invoice and the document is not legally valid.
Can an e-invoice be edited or cancelled?
Once an IRN is generated, the invoice JSON cannot be edited. It can only be cancelled — fully — within 24 hours of generation, on the IRP. After 24 hours, the only option is to issue a credit note (which itself goes through the IRP). The invoice number must not be reused.
Does HelloBooks need a separate GSP integration to push e-invoices?
No. HelloBooks integrates with Fynamics, a GSTN-authorised GST Suvidha Provider (GSP), to route IRN requests to the IRP. The integration is built in — you connect once via your GSTIN credentials, then every B2B invoice is pushed automatically when you click Save & Generate IRN.
What goes into the e-invoice schema (Form GST INV-01)?
The schema covers: supplier details (GSTIN, legal name, address), recipient details, document details (type, number, date), line items (description, HSN/SAC, quantity, rate, taxable value, GST amounts), document totals, and optional fields like Place of Supply, payment details, dispatch and ship-to addresses, e-way bill information, and reference invoice for credit/debit notes. The full schema is published at einvoice1.gst.gov.in.
Will HelloBooks generate the e-way bill alongside the e-invoice?
Yes. When you tick 'Generate EWB' on a B2B invoice, the IRN payload includes Part A and (where vehicle details are filled) Part B of the e-way bill. The IRP returns the EWB number alongside the IRN, eliminating the duplicate keying that older Tally and ERP setups required.
What happens if the IRP is down at filing time?
The IRP publishes scheduled maintenance windows and a real-time uptime status. HelloBooks queues failed IRN requests and retries with exponential backoff. If a regulatory outage is declared by the GSTN, taxpayers may continue to issue invoices and generate IRNs once the portal is back, within the 30-day window.
Where can I verify an IRN or QR code?
Use the 'Verify Signed Invoice' tool on einvoice1.gst.gov.in or scan the QR with the official GST e-invoice mobile app. The tool decodes the digital signature and confirms the IRP-issued IRN, supplier and recipient GSTIN, document totals, and date.
More on India compliance
Indian GST: CGST, SGST, IGST & Registration
Thresholds, GSTIN format, place of supply, and the rules that decide whether you charge CGST + SGST or IGST.
Read gst basicsHSN & SAC Codes for GST Invoices
How HSN (goods) and SAC (services) codes work, how many digits to print, and how HelloBooks fills them automatically.
Read hsn & sac codesE-Way Bill Rules, Distance Limits & Cancellation
When an EWB is required, validity periods by distance, Part A vs Part B fields, and the HelloBooks generation flow.
Read e-way billGSTR-1, 3B, 2B & 9 Returns: Filing Guide
What each return covers, the due dates and late fees, and how HelloBooks builds them from your books.
Read gstr returnsAuthoritative sources
GST rules change frequently. Always verify the current position with the official GSTN sources below before filing.
- GST Portal — gst.gov.inOfficial GSTN portal for registration, returns, and payments.
- CBIC GST — cbic-gst.gov.inCentral Board of Indirect Taxes & Customs — Acts, rules, notifications, and circulars.
- E-Invoice Portal — einvoice1.gst.gov.inInvoice Registration Portal (IRP) for IRN generation and e-invoice schema.
- E-Way Bill Portal — ewaybillgst.gov.inNational e-way bill portal for EWB generation, cancellation, and verification.
Run all of this on autopilot in HelloBooks
Indian GST, e-invoicing, e-way bills, and GSTR returns are built into the free plan. No add-on, no per-invoice charge.