GST E-Invoice Registration: Setup Process, Applicability and Documents

Authoritative Regulatory Advisory

GST E-Invoice Registration: Setup Process, Applicability and Documents

By Ashish Chaudhary• Managing Director

Reviewed by Ashish Chaudhary

3 min read21 October 2026

You Still Raise the Invoice. The Portal Just Signs It

A persistent misunderstanding is that e-invoicing means generating invoices on a government portal. It does not. You raise the invoice in your own system, report it to an Invoice Registration Portal, and the IRP returns an Invoice Reference Number and a digitally signed QR code. Those must appear on the invoice you give the customer. Without a valid IRN, where e-invoicing applies, the document is not a valid tax invoice.

First, confirm applicability

E-invoicing applies once aggregate turnover has exceeded five crore rupees in any financial year from 2017-18 onwards, computed across all GSTINs under the same PAN, and it is a one-way switch.

Businesses at ten crore or above must additionally report each document to the IRP within thirty days of the document date.

See our article on e-invoicing applicability for the full test and the exempt categories.

The setup

1. Register on the e-invoice portal using your GSTIN credentials. The registration is per GSTIN.

2. Choose how you will report. Three broad routes:

• Direct entry or offline utility on the portal, workable at low volume

• API integration between your accounting or ERP system and the IRP, which is the normal route at volume

• Through a GST Suvidha Provider or your software vendor, which most mid-sized businesses use

3. Set up credentials and access for the chosen route, including API credentials where applicable.

4. Map your data. The e-invoice schema has mandatory and optional fields, and your system has to produce them. This is where most of the implementation effort actually goes: HSN codes, unit codes, state codes and party details have to be complete and correctly formatted in your masters.

5. Test on a small number of documents before going live.

6. Go live, with a fallback plan for portal downtime.

What to build around it

Print the IRN and QR code on the invoice issued to the customer. An otherwise perfect invoice without them is defective where e-invoicing applies.

Reconcile e-invoice data to GSTR-1. The reported data flows into GSTR-1, so the two should agree. A difference means something was reported to one and not the other.

Reconcile to the e-way bill, where goods move, because e-way bill data and e-invoice data are compared.

Build the thirty-day discipline if you are at ten crore or above, so nothing waits for month end. After thirty days the IRP rejects the document and no IRN is generated.

Cancellation and amendment

An e-invoice can be cancelled on the IRP within a limited window. After that, the correction route is a credit note or an amendment, not a cancellation.

Verify the current cancellation window before relying on it.

What goes wrong

Masters that are not ready. Incomplete HSN codes, missing state codes, party details that do not match.

Going live without testing, and discovering the schema issues in production.

No fallback for downtime.

Printing the invoice without the QR code.

Treating e-invoicing as a finance task when it is a systems task with a finance deadline.

How Northrop LLP helps

Northrop LLP checks applicability properly, prepares the masters, sets up IRP access and integration, tests before go-live, and builds the reconciliation between e-invoice data, GSTR-1 and the e-way bill.

Frequently Asked Questions

Statutory & Procedural Answers

Does e-invoicing mean generating invoices on a government portal?

No. You raise the invoice in your own system and report it to the IRP for an IRN and QR code.

What is the thirty-day rule?

Businesses at ten crore or above must report documents to the IRP within thirty days of the document date.

Who must register?

Businesses covered by the turnover test, computed across all GSTINs under the PAN.

What if I do not print the QR code?

Where e-invoicing applies, the invoice is defective without the IRN and QR code.

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