ERPNext E-Invoicing IRN Flow Made Simple

1. What is E-Invoicing Under GST and Why ERPNext?

E-invoicing under India's Goods and Services Tax (GST) is the real-time reporting of Business to Business (B2B) tax invoices to the government's Invoice Registration Portal (IRP) before they are issued to customers. The IRP validates each invoice, assigns a unique 64-character Invoice Reference Number (IRN), returns a digitally signed QR code, and pushes the invoice data into the auto-populated GSTR-1 return and the e-Way Bill system.

ERPNext, the open-source ERP from Frappe, supports the entire e-invoicing lifecycle natively through its India Compliance app. Indian businesses use ERPNext to handle IRN generation, e-Way Bill creation, cancellation, and GSTR-1 reconciliation from a single Sales Invoice screen, without logging into the e-invoice portal manually.

Why finance teams choose ERPNext for GST e-invoicing

• Single-click IRN generation directly from the Sales Invoice.
• Automatic QR code embedding into the GST e-invoice print format.
• Bulk processing for high-volume invoicing operations.
• Combined IRN and e-Way Bill generation in a single API call.
• Built-in IRN cancellation, e-invoice logs, and exception reporting.
• Automatic data flow into GSTR-1 reconciliation reports.
• Open-source with no per-invoice fee on the application layer.

2. Who Must Generate IRN in ERPNext (Applicability 2026)

E-invoicing applicability in India is defined by Aggregate Annual Turnover (AATO). The threshold has been progressively reduced since the system was introduced in October 2020. As of 2026, every GST-registered business that crossed the threshold in any financial year from 2017-18 onwards must report its B2B invoices to the IRP and generate an IRN.

E-invoicing applicability thresholds (current as of 2026)

Who is exempt from e-invoicing

Even if turnover crosses the threshold, the following are exempt under current GST notifications:

• Special Economic Zone (SEZ) units, though SEZ developers are covered.
• Insurers and banking companies, including financial institutions.
• Non-Banking Financial Companies (NBFCs).
• Goods Transport Agencies (GTAs).
• Passenger transport service providers.
• Multiplex cinema admission ticket suppliers.
• Government departments and local authorities.

3. Prerequisites and Setup for ERPNext E-Invoicing

Before ERPNext can generate IRNs through the India Compliance app, three categories of prerequisites must be in place: master data readiness, IRP and GSP credentials, and ERPNext configuration.

3.1 Master data readiness in ERPNext

Most IRN failures originate in poor master data. Before enabling e-invoicing, validate the following:

• Active GSTIN for the supplier company, configured under the Company master.
• Customer GSTINs validated and updated, with correct State codes.
• Item master HSN or SAC codes mapped with minimum 6 digits for AATO above Rs. 5 crore.
• Place of Supply rules reviewed for inter-state, intra-state, export, and SEZ scenarios.
• Unit of Measurement (UQC) codes aligned with the GST UQC list.
• Sales Invoice naming series within 16 characters, alphanumeric only.

3.2 IRP and GSP credentials for ERPNext

ERPNext communicates with the IRP either directly through the National Informatics Centre (NIC) endpoints or through a GST Suvidha Provider (GSP). The India Compliance app supports both. Adaequare is currently the most commonly used GSP for ERPNext deployments. Other authorised options include IRIS, Cygnet, ClearTax, and Taxilla.

How to add GSP credentials in ERPNext GST Settings

Once you have created a GSP user on the e-Waybill portal (Registration menu, choose Adaequare as the GSP, set username and password), add the same credentials in ERPNext under GST Settings › Credentials tab.

3.3 ERPNext configuration: India Compliance app setup

The India Compliance app is the official open-source application for GST compliance in ERPNext. It comes pre-installed on Frappe Cloud and can be installed manually on self-hosted deployments. Configuration takes place across three documents: GST Settings, Company master, and E-Invoice Settings.

e-Waybill settings in ERPNext

Under GST Settings, configure the e-Waybill section to enable features like generation from Sales Invoice or Delivery Note, set the invoice value threshold (default Rs. 50,000), and decide whether to auto-generate e-Waybill on submission of Sales Invoice.

e-Invoice settings in ERPNext

Below the e-Waybill section, the e-Invoice Settings section turns on e-invoicing, controls auto-generation on Sales Invoice submission, and lets you generate e-Waybill together with the e-Invoice in a single API call.

Selective company-level e-Invoice settings

For multi-company ERPNext setups, you can apply e-Invoicing only to selected companies and configure an Applicable From date for each one. The retry option is recommended for production environments to handle gateway timeouts gracefully.

ERPNext e-invoicing setup steps

• Install the India Compliance app: bench get-app india_compliance, then bench install-app india_compliance.
• Open GST Settings: enable Auto Generate E-Invoice, set the e-Invoice Threshold to match your AATO, enable HSN validation.
• Open the Company master: confirm GSTIN and GST Category (Regular, SEZ, Composition).
• Open E-Invoice Settings: enter API username, password, Client ID, and Client Secret for each GSTIN.
• Enable Sandbox Mode for testing and run minimum 10 test invoices end-to-end.
• Switch off Sandbox Mode and run a single live invoice as a final validation before go-live.
• Update the GST E-Invoice Print Format to display IRN, Ack No, Ack Date, and the signed QR code.
• Configure user roles: only authorised users should have permission to generate or cancel IRN.

4. Step-by-Step IRN Generation Flow in ERPNext

Once setup is complete, the IRN generation flow runs alongside the normal sales cycle. ERPNext supports three modes: automatic generation on submission, manual generation, and bulk generation. The underlying API flow is identical across all three.

4.1 The end-to-end IRN flow

4.2 How to generate IRN in ERPNext (manual mode)

• Open the submitted Sales Invoice. The e-Invoice section appears in the form.
• Click the e-Invoice menu and select Generate IRN.
• ERPNext shows a confirmation dialog summarising the invoice value and customer GSTIN.
• Click Confirm. Within a few seconds the IRN, Ack No, Ack Date, and QR code populate.
• On failure, an error message appears with the IRP error code and explanation. See Section 7 for fixes.
• Print or email the invoice. The PDF carries the IRN and signed QR code automatically.

4.3 Automatic IRN generation on submit

If Auto Generate E-Invoice is enabled in GST Settings, ERPNext fires the IRN request the moment the Sales Invoice is submitted. The user sees a brief loading indicator, after which the IRN appears on the invoice. This is the recommended mode for production use because it eliminates the risk of users forgetting to generate IRN.

4.4 Bulk IRN generation in ERPNext

For organisations issuing many invoices per day, ERPNext supports bulk IRN generation. Navigate to E-Invoice List, filter for invoices in Pending status, select the relevant rows, and click Generate IRN. The India Compliance app processes them sequentially and reports successes and failures in a downloadable log.

4.5 Time limits you must respect

Reporting window: From 1 April 2025, businesses with AATO above Rs. 10 crore must report invoices to the IRP within 30 days from the invoice date. Beyond that window, the IRP rejects the IRN request.

Cancellation window: An IRN can be cancelled on the IRP within 24 hours of generation. After 24 hours, cancellation can only be reflected through a credit note.

5. ERPNext E-Way Bill Integration with IRN

An e-Way Bill (EWB) is required for movement of goods above a notified value, generally Rs. 50,000. ERPNext can generate the EWB in the same call as the IRN, or as a separate step.

5.1 When is an e-Way Bill required

5.2 Combined IRN and e-Way Bill generation

ERPNext exposes a single action that requests both the IRN and the EWB. On the Sales Invoice, scroll to the Transporter Info section and enter transporter GSTIN, vehicle number, distance, and mode of transport. From the e-Invoice menu, click Generate IRN and E-Way Bill. The IRP returns the IRN, signed QR, EWB number, and EWB validity date in a single response.

e-Way Bill print formats in ERPNext

Once the e-Way Bill is generated, ERPNext provides two print formats: Simplified and Detailed. The Simplified format is suitable for vehicle drivers and field staff. The Detailed format includes Part A and Part B fields, useful for the back office and for audits.

Information the dispatch team must capture

• Transporter GSTIN or transporter ID issued by the EWB portal.
• Vehicle registration number, mandatory for road mode.
• Mode of transport: Road, Rail, Air, or Ship.
• Approximate distance in kilometres between dispatch and delivery PIN codes.
• Sub-supply type: Supply, Export, Job Work, Sales Return, and similar.

5.3 e-Waybill log: tracking the audit trail

Every e-Waybill generated through the API creates an entry in the e-Waybill Log doctype in ERPNext. This log records the EWB number, generation date, validity, and any subsequent updates such as vehicle changes or extensions. It is the primary audit trail for finance and tax teams.

Updates to e-Waybill log

When you update transporter details, change the vehicle number, or extend the validity, ERPNext appends a comment to the e-Waybill Log capturing what changed and when. This timeline is invaluable during goods detention queries or GST audits.

5.4 EWB extension and vehicle update

ERPNext allows extending the validity of an EWB if goods are stuck in transit, and updating the vehicle number if there is a transhipment. Both actions create an audit trail on the Sales Invoice. EWB cancellation is supported within validity, but if validity has expired, cancel on the EWB portal and update the status manually in ERPNext.

6. IRN Cancellation and Amendment in ERPNext

The IRP does not allow editing of an IRN once generated. The only options are cancellation within 24 hours, or correction through a credit or debit note thereafter. ERPNext mirrors this behaviour with appropriate controls.

6.1 How to cancel an IRN in ERPNext (within 24 hours)

• Open the Sales Invoice that holds the IRN.
• From the e-Invoice menu, click Cancel IRN.
• ERPNext prompts for a cancellation reason: Duplicate, Data Entry Mistake, Order Cancelled, or Other.
• Confirm the action. ERPNext sends the cancellation request to the IRP and marks the IRN as Cancelled.
• Cancel the underlying Sales Invoice in ERPNext. An IRP-cancelled invoice should not remain as a Submitted Sales Invoice.

6.2 After 24 hours: corrections through credit and debit notes

6.3 Amendments through GSTR-1

Some corrections, such as a wrong invoice date, cannot be handled through credit or debit notes. These must be amended directly in the GSTR-1 return for the relevant period. ERPNext flags such cases in its e-invoice exception report so the GST team can pick them up during return filing.

7. Common ERPNext IRN Errors and How to Fix Them

Most IRN failures fall into a small set of recurring errors. The table below covers the most frequent ones, what they mean, and how to resolve them in ERPNext.

7.1 When the IRP itself is down

The Invoice Registration Portal occasionally faces outages. During such windows, the law allows businesses to continue issuing invoices, with the IRN to be obtained once the portal is restored. ERPNext should be configured to queue failed invoices automatically and retry them at a defined interval.

7.2 Escalation matrix

8. Reports and GSTR-1 Reconciliation in ERPNext

ERPNext provides a suite of reports that together give finance a complete view of e-invoicing health. Running these reports on a defined cadence is the single most effective control a finance head can put in place.

8.1 ERPNext e-invoice reports your finance team should run

8.2 Monthly GSTR-1 reconciliation

Before filing GSTR-1, the GST team should reconcile three data sets: the Sales Register from ERPNext, the e-invoice data downloaded from the IRP, and the auto-populated GSTR-1 on the GST portal. ERPNext provides a built-in reconciliation utility under the India Compliance app that highlights mismatches in invoice number, taxable value, tax amount, or customer GSTIN.

Common reconciliation differences

• Invoice issued but IRN never generated, often due to user oversight.
• IRN cancelled on the IRP but the underlying Sales Invoice not cancelled in ERPNext.
• Credit note issued in ERPNext but not reported on the IRP.
• Manual GSTR-1 edits not back-posted in ERPNext.
• Foreign currency rounding differences between IRP rate and ERPNext rate.

10. Governance Checklist for Finance Heads

Use this checklist during quarterly reviews with the GST team and the ERPNext implementation partner.