Everything About Invoice Reference Number (IRN) in e-Way bill system


Date: 29 Dec 2022

All about Invoice Reference Number (IRN)


IRN, sometimes referred to as an invoice reference number, is a special number issued by the government to determine whether the generated electronic invoice is authentic. Since its implementation in October 2020, e-invoicing has required companies to record their invoices on an invoice registration platform created by the government. To provide a standard for electronically generated invoices, the e-invoicing system was established. Everything you need to know about an invoice reference number is provided here.


What Is Invoice Reference Number

The invoice registration portal (IRP), which is part of the e-invoicing system, generates the invoice reference number, also known as a hash, using a hash creation method. A 64-character invoice reference number must be established for each document, such as an invoice, debit note, or credit note filed through the invoice registration system. Every invoice raised by a GSTIN in the entire GST system during a fiscal year would have a different ID number. 

Additionally, each invoice the provider sends to his recipient must include IRN. Through the main site and the offline app, tax officers can use an invoice reference number to confirm the genuineness of the transaction. They will then be able to check the invoices without internet access.


What Is Hash Generation Algorithm In IRN?

When a message or string of characters is transformed into a series of numbers using a hash generation technique, the resulting numbers cannot be used to decipher the original message. The GSTIN will recommend this algorithm as part of the e-invoicing requirements. 


What Are the Parameters Used To Generate an Invoice Reference Number (IRN)?

IRN is generated by converting characters into numbers using a hash generation algorithm. This algorithm will be applied to the following three parameters:

  • Supplier GSTIN

  • Supplier's document number. 

  • The financial year is in yyyy-yy format. For example, 2021-22


When Is The Invoice Reference Number (IRN) Generated?

When the seller issues the invoice, credit or debit note, the IRN creation is necessary. However, beginning on October 1, 2020, taxpayers with annual revenue of more than Rs. 500 crores would have a 30-day grace period for creating an IRN. This grace period is in effect for invoices generated between October 1, 2020, and October 31, 2020.


Any software a business uses to produce invoices will continue to be used to prepare the invoices under the e-invoicing system. However, they will need to follow the guidelines and standards that have been set.


The company can choose excel offline tool or API integration directly with the e-invoice portal/IRP or via GST suvidha provider to generate IRN.