GST e-invoicing in India: what it is, who it applies to, and how SwilERP handles it

GST e-invoicing is the single biggest compliance change Indian businesses have absorbed in the last five years. If you bill above the current turnover threshold, every B2B invoice you raise must be submitted to the GST Network's Invoice Registration Portal (IRP) before it leaves your premises — and the IRP returns a unique Invoice Reference Number (IRN) and QR code that must be printed on the bill.

This guide walks through who must e-invoice, what the IRP actually does, and how SwilERP automates the full cycle so your billing desk doesn't have to log into the portal manually.

Who has to e-invoice?

The Government has progressively reduced the turnover threshold for mandatory e-invoicing. As of August 2023, businesses with an aggregated turnover exceeding ₹5 crore in any preceding financial year must generate e-invoices for all B2B transactions.

Even if your turnover is below the threshold today, voluntary e-invoicing makes life simpler:

• GSTR-1 auto-populates from your e-invoices — no manual upload.
• E-way bills auto-fire from the IRN — no second portal login.
• Counterparty input tax credit gets verified instantly.

What the IRN actually is

The Invoice Reference Number is a 64-character hash unique to each invoice. The IRP computes it from the supplier GSTIN, the financial year, the document type, and the document number. Once issued, the IRN is the legal proof that the invoice was reported to the GST Network.

The QR code printed on the invoice encodes the IRN plus key transaction details so anyone with a scanner can verify the invoice independently — buyers, transporters, tax officers.

How SwilERP handles e-invoicing end-to-end

1. Setup once

On the GST Network e-invoice portal, register your GSTIN, generate API credentials, and paste them into SwilERP's GST settings page. After that, every B2B invoice flows through the integration automatically.

2. Bill normally

Your billing team raises invoices the same way they always have — pick the party, scan the items, apply schemes. SwilERP populates HSN, GST rate, and place-of-supply from the masters.

3. SwilERP submits to the IRP

The moment you save the invoice (or queue it for batch upload, depending on your settings), SwilERP sends the JSON payload to the IRP, retrieves the IRN and QR, and writes both back to the invoice record.

4. Print or share with the QR

Every B2B invoice print template in SwilERP includes the IRN and QR by default. The IRP-validated invoice is what you hand over to the buyer or attach to the goods.

5. E-way bill alignment

If the invoice value crosses the e-way threshold, SwilERP generates the e-way bill from the same IRN — no re-entry, no separate portal login.

Common e-invoicing errors and what to do

Error code from IRP	What it means	SwilERP behaviour
2150 — Duplicate IRN	An IRN already exists for this invoice number	SwilERP fetches the existing IRN automatically and writes it to the record
2197 — Invalid HSN	Item HSN is not in the IRP master	Invoice is held; SwilERP flags the item master for HSN correction before retry
3028 — Recipient GSTIN inactive	Buyer's GSTIN was cancelled or suspended	SwilERP warns at billing time before submission so you can switch to B2C or get a fresh GSTIN

What you save with e-invoicing in SwilERP

• Time — GSTR-1 prep drops from a half-day to a 30-minute review because every invoice is already in the GST Network.
• Disputes — buyers cannot claim "we never got the invoice" because the IRN is the legal source of truth.
• ITC accuracy — your buyers' GSTR-2A reflects your invoices the same day, so input credit conversations stop being a back-and-forth.

Get started

If you already run SwilERP, e-invoicing is part of every edition. Talk to your account manager to enable the IRP integration and validate one test invoice. If you are still evaluating SwilERP, the 45-day free trial includes full e-invoicing and e-way workflows on real data.

See SwilERP's GST billing capabilities →