What is Invoice Reference Number (IRN) in GST? Meaning, Format & Step-by-Step IRN Generation

Yarab - Tally Author

Yarab A

Updated on Apr 23, 2026

30 second summary | IRN (Invoice Reference Number) is a unique number generated under GST e-invoicing when a business uploads an invoice to the Invoice Registration Portal (IRP). An invoice is considered valid only when it includes a valid IRN and QR code, ensuring authenticity and compliance. IRN is created using key details like supplier GSTIN, invoice number, and financial year, making each invoice uniquely identifiable. E-invoicing is mandatory for businesses exceeding ₹5 crore turnover, and applies to invoices, debit notes, and credit notes. To generate IRN, businesses must upload invoice data in JSON format to the IRP, which validates the details and returns a digitally signed invoice with IRN and QR code. Using tools like TallyPrime simplifies this process by automating IRN generation, validation, and invoice printing, ensuring accuracy, compliance, and faster billing.

Invoice Reference Number (IRN) is a unique number generated by the Invoice Registration Portal (IRP) for every valid e-invoice under GST.
 in the invoice. Invoice being an important document in business, it is of utmost necessary to understand the fundamentals of IRN and the change that may be required in the way the invoices are issued.

Best e-Invoicing Software Solution for Businesses in India Generate e-Invoice Instantly in TallyPrime

Currently, e-invoicing is applicable for businesses with a turnover exceeding ₹10 crores from 1st October 2022. In the recent update, from 1st August 2023, e-Invoicing will be essential for all the registered persons whose aggregate turnover (based on PAN) in any prior fiscal year from 2017-18 onwards exceeds 5 crores. Read 'Date of implementing e-invoicing in GST' to know the e-invoicng implementation date.

In this article, we’ll discuss everything about IRN right from its meaning, format and how to generate it.

What is IRN?

IRN known as “Invoice Reference Number” is a unique invoice number generated by the Invoice Register Portal (IRP) on uploading the invoices electronically.

Under the e-invoicing system in GST, documents such as invoice, Credit Note, Debit Note or any such document as required by the law should be electronically uploaded to IRP system. Every time a unique document is uploaded in the prescribed format, a unique reference number know as 'Invoice Reference Number (IRN)' is generated by the system.

IRN is also referred to as ‘Hash’ in technical terms.

Parameters and format of IRN

The IRN is computed considering the GSTIN of a generator of the document (invoice or credit note etc.), document number like invoice number and the financial year.

  • Supplier GSTIN,
  • Supplier’s invoice number
  • Financial year (YYYY-YY)

Format of IRN

Technically, IRN is a 64-character hash value generated by the system.

You don’t need to manually create or remember it—
it is automatically generated once the invoice is uploaded to the IRP.

How to Generate IRN for e-Invoice (Step-by-Step)

The responsibility of generating e-invoice with IRN is with the creator of the document. To simplify, the responsibility of uploading tax invoice is with the supplier of goods or services. The IRP system, a portal designed to authenticate invoices, will accept invoices only in JSON format in a specified structure/schema.  

Step 1: Create Invoice Data

Generate invoice details in JSON format using:

Accounting software
Excel utilities
GST offline tools

Step 2: Upload to IRP

Upload the JSON file to the IRP portal for validation.

Step 3: Validation by IRP

The system checks:

Duplicate invoices
GST compliance
Data accuracy

Step 4: IRN Generation

Once validated:

IRN is generated
QR code is created
Invoice is digitally signed

Step 5: Receive Final Invoice

You receive:

Signed JSON
IRN
QR code

This becomes your final valid e-invoice

Simplifying IRN Generation with Software

If you’re using a business management solution like TallyPrime, the process becomes much easier:

No manual JSON creation
Direct integration with IRP
Automatic IRN & QR code generation
Invoice ready instantly

You just create and print the invoice—the system handles the rest

Why IRN is Important

IRN plays a critical role in GST compliance:

Prevents duplicate invoices
Ensures invoice authenticity
Enables real-time validation
Supports seamless tax reporting

Common Mistakes to Avoid

Generating invoice without IRN
Incorrect GSTIN or invoice number
Duplicate invoice upload
Not using proper JSON format

If you are using a business management software that is integrated with the IRP portal (via GSP to IRP), generation of IRN and QR code, and printing these details on the invoice becomes simple and seamless. It will be that simple that you just need record and print the invoice in the flow, and you will have IRN and QR code printed automatically. 

Watch How to Get IRN Info using TallyPrime

 

Watch How to Undo IRN Cancellation of e-invoice in TallyPrime

Video on e-invoicing on TallyPrime

Know more about e-invoices in GST

e-invoicing Software e-Invoice in GST
GST Invoice How to Generate E-Invoice in GST
How to Transit to e-Invoice System Invoice Reference Number (IRN)
Who Should Issue an e-Invoice in GST Generate e-Invoice Instantly in TallyPrime
How to Generate Bulk e-Invoice in TallyPrime Working of e-Invoice System

 

Published on February 24, 2020

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