How to Generate E-Invoice & IRN?

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Goods and Services Tax Act is continually upgrading to meet the requirements of the Indian business landscape. While invoicing is subjective, GST law has mandated certain organizations for the issuance of e-invoices if they cross a certain threshold. Another important concept that revolves around e-invoices is the Invoice Reference Number (IRN). What is e-invoice and IRN? How to generate e-invoices and IRN? Find out here! 

What is E-invoice? 

E-invoicing, also known as electronic invoicing, is a system whereby the invoices are electronically uploaded by the supplier and authenticated by the designated e-invoice portal. An Identification number is issued by the Invoice Registration Portal (IRP) against each invoice. This was introduced to standardize the invoice generating practice among the business houses. This enhances the inter-operability of data among businesses. 

What is an Invoice Reference Number? 

IRN, also known as Invoice Reference Number, is a 64-character unique number. It is generated by the IRP using a hash generation algorithm. The IRN is unique for each e-invoice, debit note, and credit note generated for every financial year. The IRN can be generated by either using the offline tool or through API integration.  

Applicability of E-invoice? 

E-invoicing became mandatory in a phased manner depending upon the turnover of the organisations. Following are the applicability requirements of the e-invoicing: 


Applicable on taxpayers with aggregate turnover exceeding 

Applicable From 

Rs. 500 Crores 


Rs. 100 Crores 


Rs. 50 Crores 


Rs. 20 Crores* 


5 Rs. 10 Crores 01-10-2022

*vide Notification No. 01/2022 
** vide Notification 17/2022

How to Generate E-Invoice and IRN? 

To generate an e-invoice, you need to follow the following steps: 

  • Invoice Generation: The taxpayer shall create an invoice in the e-invoice schema (format prescribed for e-invoice) using the accounting or ERP software. It shall include all the mandatory details as required by the schema. The software will generate the JSON file for the invoices created. The JSON file shall be uploaded on the IRP. 

  • Generation of IRN: A IRN will be generated by the portal using the standard hash generation algorithm. The IRN is the combination of the taxpayer’s GSTIN, document number, document type and the relevant financial year in ‘YYYY-YY’ format. 

  • Upload the Invoice: After generation of the IRN, the JSON for the invoice shall be uploaded on the IRP along with the IRN generated. This can be done directly or through the 3rd party software. 

  • Invoice Authentication and Signing: The IRP will validate the IRN attached with the JSON and authenticate the file against the central registry of the GST. After the verification is done, the IRP will add its digital signature along with a QR code to the JSON. 

  • Data Sharing and Download: The data uploaded in the IRP will be shared with the e-way bill portal and the GST portal. The digitally signed JSON, including the IRN and the QR Code, will be sent to the seller. The invoice will also be sent to the buyer on his registered mail Id. 

Mandatory Fields as per the E-invoice Schema (varies according to the nature of supply): 

E-invoice Schema is a detailed invoice format containing numerous fields. The Following fields are required as per the e-invoice schema (for the purpose of ease of understanding, the fields have been grouped category wise): 

Sr. No. 


Field Name 


Document Details 

Document Type, Number and Date  

Invoice / Debit Note / Credit Note 

Supply Details 

Type of Supply 

B2B / Supply to SEZ / Exports / Deemed Exports 

Supplier and Buyer Details 

GST Identification Number, Legal Name, Address (including state and pin code), Contact Details, Place of Supply 

Ship to Details 

GST Identification Number, address (including state and pin code)  

In the case of bill-to-ship-to supplies. 

Dispatch From 

Name of the supplier, dispatch address (including state and pin code) 

Item Details 

Item Description, HSN / SAC Code applicable, quantity, rate per unit. 

Invoice Details 

Taxable value, discount (if any), GST rate applicable, GST amount, invoice value. 

Payment Details 

Payee name, bank account details, credit period, payment due date. 

Details of Export 

Shipping bill number, port code, exchange currency, export duty applicable, country code 


Details of Transportation (Considered for e-Way Bill) 

Transport mode, vehicle number, vehicle type, distance, transport document type, transport document number. 


Any other additional details 

Author : Dipen

Date     : 29-Jun-2022