Invoice Registration Portal (IRP) Under GST: Complete Guide 2026

Latest IRP Updates for 2025-26

30-Day Reporting Rule for AATO ₹10 Crore and Above

From April 1, 2025, taxpayers with an aggregate annual turnover of ₹10 crore or more cannot report e-invoices older than 30 days from the invoice date. This restriction applies to invoices, credit notes, and debit notes that require IRN generation. If an invoice dated April 1, 2025 is not reported by April 30, 2025, the IRP will not allow IRN generation for that document after the permitted window.

MFA for IRP Login

Multi-Factor Authentication is now an important login security requirement across the e-invoice and e-way bill compliance environment. Businesses should ensure that the registered mobile number and email linked to the GSTIN are active, and that sub-users are properly configured for OTP-based access. IRIS IRP release notes also confirm mandatory MFA setup on its IRP portal.

Six Authorized IRP Portals

GSTN material confirms six authorized IRP portals for reporting e-invoices and generating IRNs free of charge.  The official overview lists the following portals: einvoice1, einvoice2, einvoice3, einvoice4, einvoice5, and einvoice6.

E-invoicing is mandatory for registered taxpayers whose aggregate turnover exceeds ₹5 crore in any preceding financial year from 2017-18 onwards, unless the taxpayer falls under an exempt category. The ₹5 crore threshold has been in effect since August 1, 2023. 

Also note that the threshold is checked at the PAN level, not only the GSTIN level . If a business crosses the notified turnover limit in any preceding financial year from 2017-18 onwards, the e-invoicing obligation continues to apply even if turnover later falls below the threshold, unless a valid exemption applies.

Which Transactions Are Covered Under IRP E-Invoicing?

E-invoicing applies to specified GST documents issued by notified taxpayers. The covered documents and supplies include:

• Tax invoices issued to registered persons, commonly called B2B invoices
• Credit notes and debit notes issued to registered persons
• Export invoices, with or without payment of tax
• Supplies to SEZ units or SEZ developers, with or without payment of tax
• Deemed exports

The following are generally outside the current IRP e-invoicing requirement and thus are not covered under IRP E-Invoicing:

• B2C invoices (may have separate QR code requirements)
• Bill of supply
• Import transactions
• Nil-rated or fully exempt outward supplies where a tax invoice is not required
• Purely commercial or financial credit notes that are not GST credit notes

Who Is Exempt From E-Invoicing?

Certain categories are exempt from e-invoicing even if their turnover crosses the prescribed threshold . Because exemptions depend on notification language and business activity, businesses should not rely only on portal enablement status. The e-invoice enablement page itself clarifies that enablement is only a facilitation tool and the legal obligation depends on Rule 48(4), notifications, and applicable exemptions. These exemption include:

What Does the IRP Do?

1. Validates Invoice Data

Once the invoice data is uploaded, the IRP checks whether the invoice JSON follows the prescribed e-invoice schema. It validates mandatory fields such as supplier GSTIN, recipient GSTIN, document type, invoice number, invoice date, HSN/SAC, taxable value, tax rate, and total invoice value.

2. Checks for Duplicate Reporting

The IRP checks whether the same document has already been reported. This helps prevent duplicate IRN generation for the same supplier GSTIN, document number, financial year, and document type.

3. Generates the IRN

The Invoice Reference Number is a unique hash generated for the invoice. It is based on key invoice parameters such as supplier GSTIN, document number, financial year, and document type.

4. Digitally Signs the Invoice Data

After successful validation, the IRP digitally signs the invoice JSON. The signed JSON is the authenticated e-invoice data.

5. Generates the Signed QR Code

The IRP generates a signed QR code containing key invoice details such as supplier GSTIN, recipient GSTIN, invoice number, invoice date, invoice value, number of line items, HSN of the main item, IRN, and IRN date. This QR code helps buyers, auditors, and tax officers verify the invoice.

6. Shares Data With the GST System

Once IRN is generated, the invoice details are shared with the GST system. Relevant e-invoice details then auto-populate in GSTR-1 tables, subject to system processing and taxpayer review.

7. Supports E-Way Bill Flow

Where an e-way bill is required, e-invoice data can be used for e-way bill generation . This reduces repeated data entry because invoice details already authenticated by the IRP can flow into the e-way bill system.

How to Register on an IRP Portal

Eligible taxpayers must be enabled and registered for e-invoicing before reporting invoices. GSTN material states that enabled taxpayers must register on any of the six IRPs before they can start reporting e-invoices. The onboarding process involves one-time verification of the taxpayer’s registered mobile number and email through OTP.

Step 1: Check E-Invoice Applicability

First, verify whether your aggregate turnover has crossed the notified threshold and whether your business falls under any exempt category. Do not rely only on portal enablement status because legal applicability depends on GST rules and notifications.

Step 2: Visit an Authorized IRP

Taxpayers can use any authorized IRP. The government e-invoice system lists six active IRP portals, from einvoice1 to einvoice6.

Step 3: Enter GSTIN and Verify Details

Enter your GSTIN and complete the verification process. The system fetches GST registration details linked to the GSTIN.

Step 4: Complete OTP Verification

An OTP is sent to the registered mobile number and email address. Complete verification to create login credentials.

Step 5: Set Up MFA and User Access

Enable MFA and ensure that all users who need portal access have updated mobile numbers and valid credentials. For businesses with multiple users, create sub-users instead of sharing one login across teams.

Step 6: Configure API Access if Required

If invoices are generated through ERP or accounting software , configure API access through your software provider, GSP, or direct API route where available. This helps report invoices in real time and reduces manual upload errors.

How to Generate an E-Invoice on the IRP

Step 1: Create the Invoice in Your Accounting Software

Create the invoice in your ERP, billing, or accounting software . The invoice must contain all required GST invoice details and must be convertible into the prescribed e-invoice JSON schema.

Step 2: Validate Mandatory Details

Before reporting to the IRP, check:

• Supplier GSTIN
• Recipient GSTIN
• Invoice number
• Invoice date
• Document type
• Place of supply
• HSN or SAC code
• Taxable value
• GST rate
• Tax amount
• Total invoice value

From June 1, 2025, the IRP treats invoice numbers as case-insensitive for IRN generation, based on GSTN advisory coverage. This means invoice numbers that differ only by uppercase or lowercase letters can be treated as the same for duplicate checking. Businesses should keep invoice numbering consistent in their billing software.

Step 3: Upload or Report the JSON to the IRP

You can report the invoice through an offline utility, a web tool, an API, mobile mode (where available), or a GSP/software integration. GSTN’s e-invoice overview notes that most IRPs provide offline tools, online web tools, mobile apps, and API-based methods.

Step 4: Receive IRN and Signed QR Code

If validation is successful, the IRP generates the IRN, digitally signs the invoice data, and returns the signed QR code . This authenticated data should be printed or embedded on the invoice shared with the buyer.

Step 5: Share the Valid E-Invoice With the Buyer

The invoice issued to the buyer should carry the IRN and QR code. Without a valid IRN, an invoice covered under Rule 48(4) is not treated as a valid invoice under Rule 48(5).

Modes of Reporting Invoices to the IRP

Web-Based Upload

This is useful for businesses with lower invoice volumes. The user enters or uploads invoice details using the IRP utility or portal and downloads the signed output after validation.

Offline Excel or JSON Utility

The offline tool helps prepare invoice data in the required JSON format . This works for businesses that do not have direct software integration but still want bulk upload support.

API Integration

API integration is suitable for businesses that generate a high number of invoices. It connects accounting or ERP software directly with the IRP or through an approved provider. This reduces manual work and helps avoid missing the 30-day reporting window.

GSP or Software-Based Integration

Many businesses prefer using accounting software or a GST Suvidha Provider to manage validations, API connectivity, error tracking, bulk reporting, and e-way bill linkage. This is usually more practical than manually uploading JSON files every day.

This is where BUSY Accounting Software can be useful for Indian businesses. BUSY helps users create GST invoices, manage accounting and inventory, and streamline e-invoice and e-way bill workflows from one system, reducing manual portal work and data mismatch risks.

For small and mid-sized businesses, the practical choice is usually not about the IRP portal alone. It is about how easily the IRP connects with their accounting software, how well errors are handled, and whether the team can generate e-invoices without repeatedly logging into government portals.

If your invoice volume is low, a web or offline utility may be enough. If your business issues many B2B invoices, handles e-way bills, or has multiple branches, API-based software integration is usually safer because it reduces manual data entry and helps report invoices on time.

Cancellation and Correction of E-Invoices

Once an IRN is generated, the invoice cannot be edited directly on the IRP. If there is a mistake, the correction route depends on when the mistake is found and what type of error it is.

Cancellation Within 24 Hours

An e-invoice can generally be cancelled on the IRP within 24 hours of IRN generation. Cancellation must be for the full invoice. Partial cancellation of line items is not allowed. If an e-way bill is already linked and active, the e-way bill may need to be cancelled first before the IRN can be cancelled.

Correction After 24 Hours

After 24 hours, the IRP cancellation window is not available. The taxpayer should use the appropriate GST correction route, depending on the issue.

GSTR-1 Auto-Population From IRP Data

The GST portal FAQ confirms that e-invoice data is auto-populated into tables such as B2B invoice tables, export invoice tables, and credit/debit note tables.

Taxpayers can edit auto-populated e-invoice details in GSTR-1. However, when edited, the source, IRN, and IRN date fields can become blank, and the record may be treated as manually uploaded rather than auto-populated. This is why businesses should not blindly file GSTR-1 only because data has auto-populated. They should reconcile IRP data, books, and GSTR-1 before filing.

Penalties and Business Risks

If a notified taxpayer issues an invoice without following Rule 48(4), Rule 48(5) says that such invoice will not be treated as an invoice. This creates both compliance and business risks. Penalty exposure depends on facts, offence category, and applicable GST provisions. Section 122 contains penalty provisions for invoice-related and tax-related offences. Common risk areas include:

Conclusion

The Invoice Registration Portal is now a core part of GST compliance for Indian businesses covered under e-invoicing. It validates invoice data, generates the IRN, digitally signs the invoice, creates the QR code, and helps auto-populate GST return data.

For 2025-26, the most important compliance points are clear. Businesses above the ₹5 crore e-invoicing threshold must follow IRP reporting rules unless exempt. Businesses with AATO of ₹10 crore or more must also follow the 30-day reporting limit. There are six authorized IRP portals, and MFA should be treated as part of the regular login and security process.

The best approach is to generate invoices through reliable accounting software , validate data before reporting, generate IRNs on time, reconcile GSTR-1 before filing, and keep buyer ITC impact in mind. For businesses using BUSY Accounting Software, e-invoicing can become part of the normal billing workflow instead of a separate manual compliance task.