How to Generate an E-Invoice and IRN Under GST

The accounting system has created an invoice number, but it is not yet an e-invoice. The eligible document must be validated, reported to an authorised IRP and returned with an IRN, acknowledgement and signed QR before the controlled invoice output is complete.

That is why this guide starts with the decision, not the form. The goal is to leave you with a short evidence list, a clear owner and a next action that does not overstate what software or a portal screen can decide.

The Short Answer

Confirm applicability and document scope, validate supplier/buyer, document, supply, HSN, tax, place-of-supply and value data, submit the prescribed JSON through an authorised IRP route, receive the IRN and signed QR, and attach that response to the business invoice record. From June 2025 IRP treats document numbers case-insensitively by converting them to uppercase for IRN generation.

Last reviewed: 30 September 2026. Due dates, portal validations and notification-based exceptions can change. Verify the live portal and current primary source before acting.

In Plain Words

Separate preparation from submission. A readiness check should block missing or inconsistent fields before the provider call. Preserve the exact request/response, IRN, acknowledgement, QR and any cancellation reason. Never silently regenerate a different business invoice after an error.

Use three separate columns in your working: what your books say, what the GST system says, and what the law or current official guidance requires. Those columns often overlap, but they are not interchangeable. Keeping them separate prevents a software status or portal total from becoming an unsupported tax conclusion.

Why This Problem Happens

Teams usually begin with a remembered threshold, a dashboard number or a message from another party. The underlying evidence arrives later and may tell a different story. Names, GSTINs, periods, document numbers, State rules, amendments and timing can each change the answer.

The practical fix is a repeatable review trail. Record the source, the period, the exception, the person responsible and the evidence that closes it. If a fact changes later, update the working rather than silently rewriting history.

The Decision Framework

Identify the event. What registration, return, invoice, movement, payment or notice is actually in question?
Fix the period and parties. Confirm GSTIN, PAN, State, counterparty and relevant tax period.
Compare the evidence. Put source documents, books and portal data side by side.
Apply the current rule. Use the official source linked below and record any exception.
Approve and retain proof. Keep the working, submission and acknowledgement together.

Decision checklist for How to Generate an E-Invoice and IRN Under GST

Step-by-Step Checklist

Confirm mandate, exemption and document scope. Add the supporting record to the working and assign a named owner before moving to the next step.
Validate invoice master and transaction fields. Add the supporting record to the working and assign a named owner before moving to the next step.
Submit to an authorised IRP and store the signed response. Add the supporting record to the working and assign a named owner before moving to the next step.
Render IRN/QR, control cancellation and reconcile to GST records. Add the supporting record to the working and assign a named owner before moving to the next step.

Do not mark a step complete because someone says it was done. Mark it complete when the relevant source document, portal evidence or approval is attached.

Worked Example

INV/26-27/001 becomes the source document. The system validates buyer GSTIN, supply type, item values and tax; submits the JSON; receives IRN/acknowledgement/QR; and stores them against that invoice. If the IRP rejects a value mismatch, correct the source data deliberately before retrying.

The numbers and names in this example are illustrative. The control is the important part: preserve the original record, explain the difference and record the authorised decision. That creates a file another accountant or officer can follow without guessing.

Worked evidence example for How to Generate an E-Invoice and IRN Under GST

Documents and Evidence to Keep

source invoice
validated IRP JSON
IRN acknowledgement and signed QR
error/cancellation log
GSTR-1 reconciliation

Keep the final submission or action proof beside this pack. A screenshot without the underlying source, or a source document without the filed acknowledgement, leaves half an audit trail.

Exceptions and Edge Cases

The answer can change where there are several GST registrations under one PAN, supplies across States, exports, e-commerce operators, reverse charge, amendments, credit notes, cancelled documents or a portal notice. Treat each as a separate branch in the working.

When two official pages appear inconsistent, prefer the later notification, circular or current portal manual and record the date checked. Old official FAQs can remain online after a rule or system validation changes.

Common Mistakes

calling a PDF an e-invoice
submitting before master-data validation
losing the signed IRP response
creating duplicate IRNs by changing document-number case

These mistakes share one pattern: a conclusion is made before the evidence is reconciled. Slow down at the decision point, not after submission.

How Truetal Helps — and Where It Stops

Truetal supports e-invoice preparation and keeps invoice data, IRN readiness and the underlying business record together for review.

Eligibility and exemptions remain the taxpayer’s responsibility. Verify current notifications and provider readiness before relying on any automated step.

That boundary is deliberate. Software should organise evidence, highlight exceptions and preserve decisions; it should not invent legal certainty or silently post a tax-affecting conclusion.

FAQ

What should I check first: Generate E-Invoice and IRN?

Confirm mandate, exemption and document scope. Start with the source facts and the current official portal or notification. A headline threshold or a verbal assurance is not enough when the answer depends on entity, period, State, document type or transaction flow.

Which records should I keep?

Keep source invoice, validated IRP JSON, IRN acknowledgement and signed QR, plus the final acknowledgement, working and approval. Records should show what the business knew, what decision it made, who approved it and what was finally submitted or changed.

What is the most common mistake?

A common mistake is calling a PDF an e-invoice. The safer control is to preserve the source record, name the precise exception and close it with evidence rather than changing a number simply to make two totals agree.

How does Truetal help?

Truetal supports e-invoice preparation and keeps invoice data, IRN readiness and the underlying business record together for review. Eligibility and exemptions remain the taxpayer’s responsibility. Verify current notifications and provider readiness before relying on any automated step.

The Takeaway

Start with the source record, separate books from portal data, apply the current rule and close the exception with proof. Set Up E-Invoicing when you are ready to turn the issue into a controlled next step.

Sources

This is general information, not legal or tax advice. Verify the facts, effective date and current notification for your business before acting.