Generating an E-Invoice: IRN, QR Code and Cancellation

E-invoicing does not mean the Government writes the invoice. The business still raises it in its own billing system. What changes is the order of events. The invoice data goes to an Invoice Registration Portal (IRP) first. The IRP checks it, gives it a unique Invoice Reference Number (IRN), signs it and returns it with a QR code. Only then is the document an invoice. Most difficulties come from what the IRP will not accept, and from what cannot be undone once it has accepted something.

This guide covers the mechanics. Who must e-invoice is in the previous guide. Errors and their consequences are in the next.

The legal basis

Rule 48(4) requires a notified person to prepare its invoice “by including such particulars contained in FORM GST INV-01 after obtaining an Invoice Reference Number by uploading information contained therein on the Common Goods and Services Tax Electronic Portal”.

Each part of that sentence is defined elsewhere:

• The form. FORM GST INV-01 is the e-invoice schema. Its present text, schema version 1.1, was substituted by Notification No. 60/2020-Central Tax.
• The portal. Notification No. 69/2019-Central Tax, issued under section 146, notifies www.einvoice1.gst.gov.in to www.einvoice10.gst.gov.in as the common portal for rule 48(4).
• The QR code. Rule 46®, inserted by Notification No. 72/2020, makes a “Quick Response code, having embedded Invoice Reference Number (IRN) in it” a required particular of an invoice issued under rule 48(4).

The IRPs

Until 2023 the National Informatics Centre (NIC) ran the only IRP. In 2023 GSTN empanelled four private IRPs. Its advisory lists six portals authorised to generate IRNs:

Portal	Operator
einvoice1.gst.gov.in	NIC
einvoice2.gst.gov.in	NIC
einvoice3.gst.gov.in	Cygnet
einvoice4.gst.gov.in	ClearTax
einvoice5.gst.gov.in	E&Y
einvoice6.gst.gov.in	IRIS Business

A supplier may use any of them. All IRPs check each document against one central registry, so a document can be registered only once whichever IRP is used. GSTN’s search facility at einvoice.gst.gov.in, and the IRPs’ mobile apps, verify IRNs from any IRP.

Before the first invoice: registration and login

Registration on the IRP is separate from GST registration. The e-invoice portal’s FAQs say:

• A GSTIN that is already registered on the e-way bill portal uses the same username and password.
• Otherwise the supplier registers on the e-invoice portal. It enters its GSTIN, receives an OTP on the mobile number registered on the GST portal, and creates a username and password.
• IRN generation is allowed only for an active supplier. A supplier whose registration is cancelled or suspended cannot generate IRNs.

Multi-factor authentication. GSTN’s advisory of 17 December 2024 described a login of username, password and an OTP sent to the registered mobile number. MFA had been mandatory since 20 August 2023 for taxpayers with annual aggregate turnover above Rs 100 crore. The advisory announced its extension:

• from 1 January 2025, for turnover above Rs 20 crore
• from 1 February 2025, for turnover above Rs 5 crore
• from 1 April 2025, for all other taxpayers and users

The registered mobile number on the GST portal must therefore be current. A change is made through an amendment of registration.

Four ways to report

The NIC portal’s documents and FAQs describe these modes:

• API, directly from the supplier’s ERP, or through a GST Suvidha Provider (GSP). The supplier gets API access on the portal, and IP addresses already whitelisted for the e-way bill API can be used.
• The bulk generation tool. A downloadable Excel utility converts invoices to a single JSON file. The file is uploaded under the bulk upload option, up to 2 MB per file.
• GePP, the browser-based e-invoice preparation portal at gepp.einvoice1.gst.gov.in. The FAQs describe it as being for suppliers without an ERP system.
• The private IRPs’ own utilities, which differ from portal to portal.

What the schema requires

The IRP accepts only JSON that conforms to INV-01. The NIC schema marks seven blocks as mandatory, each with mandatory fields:

Block	What it holds	Mandatory fields
Version	Schema version	1.1
TranDtls	The transaction	Tax scheme; supply type (B2B, SEZWP, SEZWOP, EXPWP, EXPWOP or DEXP)
DocDtls	The document	Type (INV, CRN or DBN); number; date
SellerDtls	The supplier	GSTIN, legal name, address, location, PIN, state code
BuyerDtls	The recipient	GSTIN, legal name, place of supply, address, location, state code
ItemList	Each line	Serial number; whether a service; HSN; unit price; gross amount; taxable value; GST rate; total item value
ValDtls	The totals	Total taxable value; total invoice value

Optional blocks carry dispatch and ship-to addresses, export details, payment terms, references to earlier documents and e-way bill details. Reverse charge and e-commerce flags sit in the transaction block. INV-01 itself marks each field “Mandatory” or “Optional”.

The schema validations reject documents for common reasons:

• Document number. It must not start with “0”, “/” or “-”.
• HSN. Each line needs a valid HSN of at least four digits, from the services range where the line is a service.
• Goods lines. Quantity and unit quantity code are mandatory for goods.
• The recipient. Its GSTIN must be active or suspended on the document date. A cancelled GSTIN is accepted only for documents dated between its registration and its cancellation.
• Arithmetic. Item and invoice totals must agree within a tolerance of about one rupee.
• Size. No more than 1,000 lines, and no more than 2 MB of JSON.
• Values. All values are in rupees. Foreign currency can go only in optional fields.

What the IRP returns

The IRP computes the IRN as a 64-character hash of four items: the supplier’s GSTIN, the financial year, the document type and the document number. It checks the hash against the central registry. If the same document has already been registered, through any IRP, it rejects the request. If not, it signs the JSON with its own key and returns:

• the IRN
• an acknowledgement number and date
• the signed invoice
• a signed QR code

The supplier’s own signature is not needed. A proviso to rule 46 dispenses with it for an invoice issued electronically under the Information Technology Act. The NIC FAQs say a registered e-invoice is available on the portal for reference for only 24 hours. The supplier keeps its own copy.

The QR code

According to NIC’s documentation, the signed QR code contains:

• the supplier’s and recipient’s GSTINs
• the invoice number, type and date
• the invoice value
• the number of line items
• the HSN of the line with the highest taxable value
• the IRN and the date it was generated

The code is signed, so anyone can check it offline with the verification app. Tampering makes the signature fail.

The FAQs say the QR code “has to be printed by the tax payer on the invoice copy issued to buyer” and that “printing of QR code on separate paper is not allowed”. Its size and position on the invoice are left to the business, as long as it can be scanned. In transit, rule 138A(2) allows the QR code with the embedded IRN to be “produced electronically” instead of a physical copy of the invoice.

The 30-day reporting limit

Rule 48(4) has no time limit for reporting. The limit comes from IRP validation, announced by GSTN advisory:

• 13 September 2023. IRPs would not accept e-invoices more than 30 days old from taxpayers with annual aggregate turnover of Rs 100 crore and above.
• 5 November 2024. From 1 April 2025, the limit applies to taxpayers with annual aggregate turnover of Rs 10 crore and above. It covers “all document types (Invoices/Credit Notes/Debit Notes)”. The advisory gives an example: an invoice dated 1 April 2025 “cannot be reported after 30th April 2025”.

The same advisory says there is “no such reporting restriction on taxpayers with an AATO of less than 10 crores as of now”. No later advisory has extended the limit to them. A business between Rs 5 crore and Rs 10 crore therefore faces no portal block on late reporting. The legal consequence of late reporting is a separate matter, covered in the next guide.

Cancellation: 24 hours, whole documents only

The NIC user manual and FAQs set the rules for cancellation:

• 24 hours. Cancellation “is possible only within 24 hours of the generation of the IRN”. It is done under the Cancel option, giving a reason and remarks, or in bulk by uploading a cancellation JSON file.
• Whole documents. “E-Invoice/IRN can’t be partially cancelled. It has to be fully cancelled.”
• Not with a live e-way bill. Cancellation “is not possible in case the e-way bill is already generated/active for the respective IRN”. The e-way bill has to be cancelled first.
• No reuse of the number. Once an IRN is cancelled, the same document number cannot be used to generate an IRN again. A replacement document needs a new number.
• No edits. An IRN “cannot be modified or deleted”. The FAQs give one route for an error found within the window: “cancel that invoice/IRN and report a new document (with new number)”.

After 24 hours the IRP offers nothing. GSTN’s detailed overview of the system states that amendment of an e-invoice already uploaded “will be done only on GST portal, while filing GSTR-1” and “is not possible through the IRP”. The options after 24 hours are covered in the next guide.

Where the data goes next

GSTR-1. The GST portal takes the e-invoice data from the IRP and fills the supplier’s GSTR-1:

• tables 4A, 4B, 4C, 6B and 6C (B2B invoices)
• table 6A (exports)
• table 9B (credit and debit notes)

The records can be edited before filing. When one is edited, the portal clears its Source, IRN and IRN Date fields. The detail is in the guide on filing GSTR-1. From there the records reach the recipient’s Invoice Management System and GSTR-2B.

The e-way bill. Rule 138A(3) provides that Part A of the e-way bill “shall be auto-populated by the common portal” from the INV-01 data. The supplier can generate the e-way bill with the IRN in one request, by including transport details and distance, or later from the IRN.

According to the schema validations:

• No e-way bill is generated for a credit note, a debit note, or a document with only services lines.
• If only a transporter ID is given, only Part A is generated.
• The distance must be within 10 per cent of the system’s PIN-to-PIN distance.

The June 2026 change. GSTN announced on 17 June 2026 changes to the e-invoice API and the e-way bill by IRN API. The change requires the ship-to GSTIN to be captured in bill-to/ship-to transactions, with “URP” for an unregistered consignee. GSTN gave 1 August 2026 as the date for production. When e-way bills are needed is covered in the guide on when one is needed.

The procedure in order

1. Register on an IRP, or log in with e-way bill credentials, with MFA on the registered mobile number.
2. Raise the invoice, credit note or debit note in the billing system with the INV-01 mandatory fields and a document number unique for the financial year.
3. Report it to an IRP by API, the bulk tool, GePP or a private IRP’s utility. Taxpayers at Rs 10 crore and above report within 30 days of the document date.
4. Receive the IRN, acknowledgement and signed QR code, and print the QR code on the invoice copy issued to the buyer.
5. Generate the e-way bill with the IRN or from it, where goods move.
6. Check the auto-populated GSTR-1 tables before filing.
7. To undo a document, cancel the whole IRN within 24 hours, after cancelling any e-way bill. After that, use the GSTR-1 and credit note routes.

The next guide covers what happens when an e-invoice is missed or wrong: rule 48(5), the recipient’s credit, penalties and the courts’ approach in transit cases.