E-Invoicing in India: Who Needs It, How It Works, and What Changes

E-invoicing under GST has gradually expanded since 2020, and most growing Indian businesses now fall within its scope. Despite the name, e-invoicing isn't about emailing PDFs — it's a specific government-prescribed process that turns each B2B invoice into a registered, validated document. Here is what every business in scope needs to know.

What e-invoicing is — and isn't

E-invoicing is not issuing an invoice electronically (you've been doing that with PDFs for years). Under GST, e-invoicing means:

• Each B2B invoice is uploaded to the Invoice Registration Portal (IRP) in a prescribed JSON format
• The IRP validates it and assigns a unique Invoice Reference Number (IRN)
• The IRP also generates a QR code containing key invoice details
• The IRN and QR code must appear on the invoice you give to your customer
• Without an IRN, the invoice is not a valid tax invoice

So an "e-invoice" is really an IRP-registered invoice.

Who is required to e-invoice

E-invoicing applies based on aggregate annual turnover in any preceding financial year from 2017-18 onwards. The threshold has been progressively lowered:

• October 2020: ₹500 crore and above
• January 2021: ₹100 crore
• April 2021: ₹50 crore
• April 2022: ₹20 crore
• October 2022: ₹10 crore
• August 2023: ₹5 crore and above

As of the latest, businesses with aggregate turnover exceeding ₹5 crore in any FY from 2017-18 onwards must e-invoice their B2B supplies. The threshold may be lowered further; check the latest CBIC notifications for the current state.

Who is exempt

Some categories are explicitly exempted regardless of turnover:

• SEZ units (though SEZ developers must e-invoice)
• Insurance companies
• Banking and financial institutions, NBFCs
• Goods Transport Agencies (GTAs) — for transport of goods by road
• Passenger transport services
• Multiplex cinema ticket services
• Government departments and local authorities

If you're in one of these categories, e-invoicing doesn't apply even above the turnover threshold.

What transactions are covered

E-invoicing applies to:

• B2B supplies (registered recipient)
• Exports (with or without payment of tax)
• Deemed exports
• Supplies to SEZ units / developers (with or without payment of tax)

E-invoicing does not apply to:

• B2C invoices (though B2C invoices above ₹500 from notified businesses need a QR code — different rule)
• Bill of supply (for exempt supplies)
• Delivery challans (not invoices)

The flow, step by step

For an in-scope B2B invoice:

1. Generate the invoice in your accounting software in the prescribed JSON format
2. Upload to the IRP via direct API, GSP (GST Suvidha Provider), or bulk upload
3. IRP validates — checks GSTIN of supplier and recipient, basic format
4. IRP returns the IRN and a signed QR code containing key details
5. Embed IRN and QR code on the printable invoice
6. Issue the invoice to your customer
7. Auto-populate GSTR-1 (the IRP shares the data) and the e-way bill system (if applicable)

The process is meant to be invisible to the user once integrated — your accounting software handles the API calls.

The 30-day rule

As of mid-2023, taxpayers above ₹100 crore turnover must register the IRN within 30 days of the invoice date. The window has been progressively considered for lower-turnover taxpayers too — verify the current rule for your turnover band.

Practical implication: backdating invoices to dates more than 30 days prior doesn't work anymore. The discipline of timely e-invoicing matters.

Consequences of not e-invoicing when required

A B2B invoice issued by a taxpayer required to e-invoice but without an IRN is not a valid tax invoice under GST. The consequences:

• The recipient cannot claim ITC on it
• You may face penalties for not following the rules (₹10,000 per invoice or ₹25,000 for failure to keep records)
• Your GSTR-1 auto-population from the IRP doesn't work; you have to manually report (and the GSTN may detect the discrepancy)

The customer feedback loop is the most immediate consequence — your B2B customers will refuse the invoice and demand re-issuance with an IRN, blocking the receivable.

How e-invoicing changes your daily process

For most businesses already running modern accounting software, the change at the user level is minimal:

• You raise an invoice as before
• The software submits it to the IRP behind the scenes
• The IRN comes back in 1-2 seconds
• The printed invoice now includes the IRN and QR code

What changes operationally:

• Cancellations and amendments are subject to time limits — you can cancel an e-invoice within 24 hours but cannot modify it (issue a credit note instead)
• GSTR-1 reconciliation becomes more rigid — what's in the IRP is the source of truth
• E-way bill generation can use the IRN, simplifying the flow

Choosing how to connect to the IRP

Three main paths:

• Direct API — your software connects directly to the IRP. Requires development effort; gives the most control.
• GSP (GST Suvidha Provider) — third-party intermediary that handles the IRP connection. Easier to set up; small per-invoice cost.
• Bulk upload tool — for businesses with low invoice volume; upload daily

Most growing businesses on modern accounting software use a GSP integration that's pre-built. Bulk upload is a fallback for very small volumes.

Common issues

Some recurring trouble spots:

• Wrong GSTIN — recipient GSTIN typos cause IRP rejection. Validate GSTINs on customer setup.
• HSN code missing — see our HSN code post.
• Place of supply confusion — the recipient's state vs the supply location
• Amount mismatch — line totals not matching invoice total

The IRP rejects invoices with errors; the rejection message tells you what's wrong. Most issues are first-time setup problems that go away once your master data is clean.

How Booksmor helps

Booksmor integrates with the IRP via a GSP — every B2B invoice in scope is automatically submitted, the IRN and QR code are included on the printable invoice, and 24-hour cancellation handling is built in. GSTR-1 stays aligned with the IRP; e-way bill generation uses the IRN. Start a 30-day free trial and stop worrying about e-invoice compliance.