What is an Invoice Reference Number?

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What is an Invoice Reference Number? 

Being implemented from 1st October 2020, the e-invoice generation requirement has become mandatory for organizations crossing certain threshold limits. The requirement of generating e-invoice, and correspondingly the IRN, has been implemented in a phased manner. Vide Notification No. 17/2022, generation of e-invoice has become mandatory for taxpayers with an annual aggregate turnover exceeding Rs. 10 crores. Let’s see How IRN and e- invoice is linked.

What is an Invoice Reference Number? 

Invoice Reference Number, also known as IRN, is a unique reference number (also called a hash) allotted by Government to each e-invoice generation. It is generated by the Invoice Registration Portal (IRP) using the hash generation algorithm for each invoice, credit note, and debit note submitted in the IRP. The IRN is 64 characters long and will be unique for every invoice created in a financial year. 

The invoice reference number is generated by combining the following characters into a unique reference number: 

  • The supplier GST Identification Number 

  • The supplier’s document number i.e., invoice number or debit/credit note number 

  • The relevant financial year in ‘YYYY-YY’ format, for instance, 2022-23. 

How the Invoice Reference Number can be Generated? 

The invoice reference number can be generated using the accounting or ERP software used by the organization. Using your accounting or ERP software, you can generate e-invoice data and create a JSON file. The IRP system will validate the data provided and generate the IRN for each invoice. Once the e-invoice data is successfully validated, the digitally signed JSON along with the IRN will be sent to the supplier. IRN can be generated through the following two modes: 

A. Using the Offline Tool 

By using the offline utility, you can upload and generate the e-invoices in bulk using the bulk generation tools. Visit the e-invoice portal where you can find the utility in Help >> Tools >> Bulk Generation Tools. Select the format that suits your needs, enter the requisite details and upload the same. This will generate a unique IRN for each invoice. These can be downloaded in excel format from the portal. 

B. Using Application Programming Interface (API) 

Through API, IRN can be generated by any of the following methods: 

  1. Through GSP Integration: Using the API, systems can be integrated with the help of registered GST Suvidha Providers (GSP). The GSP needs to get registered in the e-invoice portal, if not already registered. However, if the taxpayer is using the same GSP for the e-way bill portal, then the same credentials can be used. 
  2. However, before proceeding with this method, the API integration with the GSP will be tested in a sand-box environment. After the test is completed, the GSP will submit the test summary report on the sand-box portal. An API user shall be created using a username and password. Once created, a token and request for the IRN shall be generated. 
  3. Through Direct Integration: Here, the taxpayer’s systems can be directly integrated. Firstly, the API integration shall be tested in a sand-box environment. After the test is completed, the taxpayer shall submit the test summary report on the sand-box portal. Same as GSP, the taxpayer shall get itself registered on the e-invoice portal. However, if he is registered on the e-way bill portal, then the same credentials can be used.  
  4. Through Sister Concern’s GSTIN: The system can also be integrated using API via sister concern’s GSTIN having the same PAN as the taxpayer. Other points are similar to the above. 
  5. E-way bill API-enabled taxpayers: Those taxpayers having registration on the e-way bill portal can integrate their system using the API. Other points are similar to the above. 


Author : Dipen

Date     : 29-Jun-2022


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