Free Tools For Generating E-Invoices

Free Tools For Generating E-Invoices

If your aggregate turnover crossed ₹5 crore in any financial year from FY 2017-18 onwards, you must generate an Invoice Reference Number (IRN) for every B2B invoice, export invoice, credit note, and debit note you raise — regardless of individual transaction size. GSTN and NIC have made this achievable without any software purchase. The free tools — a browser portal, a bulk Excel utility, and a mobile app — are officially supported and sufficient for businesses raising up to 200 invoices a month. Here is exactly how to use each one.

What E-Invoicing Actually Does Under GST

E-invoicing is not a separate invoice format. It is a registration process: before you send an invoice to your buyer, you submit it to an Invoice Registration Portal (IRP), which validates the data, assigns a unique 64-character IRN (a deterministic hash of your GSTIN + financial year + document type + document number), digitally signs the JSON, and returns a QR code. You embed that IRN and QR code on your invoice PDF and then dispatch it to the buyer.

Why this matters in practice:

• The digitally signed JSON returned by the IRP is the legally valid tax invoice under Section 31 of the CGST Act, 2017. An invoice missing an IRN — where one is mandated — is not a valid tax document, regardless of how well it is formatted.
• The IRP pushes invoice data to the GST portal, which auto-populates Table 4 of GSTR-1. Your buyer sees the inward supply in GSTR-2B the following month with no manual entry required. No IRN means no auto-population — your buyer's reconciliation team will flag you, and the relationship cost accumulates quickly.
• The QR code on the printed invoice lets tax officers and procurement teams verify the invoice's authenticity without portal access, which is increasingly a procurement compliance requirement for large buyers.

The IRP acts as a pass-through registration desk, not a permanent archive. Your own ERP, accounting software, or a downloaded signed JSON remains your primary record.

Who Must Generate E-Invoices in FY 2026-27

The applicable threshold, as notified under the CGST Act, is aggregate turnover above ₹5 crore in any financial year from FY 2017-18 onwards. "Aggregate turnover" follows the same definition as under GST registration: all taxable, exempt, zero-rated, and non-GST supplies across all GSTINs of a PAN.

Documents that require an IRN:

• B2B tax invoices (supplies to registered buyers, including SEZ units and developers as buyers)
• Export invoices — with or without IGST payment (EXPWP / EXPWOP)
• Credit notes and debit notes under Section 34
• Supplies to SEZ developers and SEZ units acting as buyers

Documents that do not require an IRN:

• B2C invoices (unregistered buyers) — though a QR code on a dynamic basis is required for B2C supplies exceeding ₹2,50,000 in certain categories
• Bill of supply (for exempt or composition supplies)
• Delivery challans
• Input service distributor invoices

Notified exempt supplier categories — these businesses are not required to generate e-invoices regardless of turnover:

• Banking companies, NBFCs, and insurance companies
• Goods Transport Agencies (GTA)
• Passenger transport service providers
• Multiplex cinema operators
• SEZ units (as suppliers — but not as buyers)
• Government departments and local authorities as suppliers

If you operate in any of these categories, verify your exempt status against the latest CBIC notification each financial year. The list has been refined through successive notifications since 2020.

The Free Tools: A Practical Comparison

There are currently six notified IRPs in India. NIC (National Informatics Centre) operates two — einvoice1.gst.gov.in and einvoice2.gst.gov.in — and is the natural starting point for small taxpayers because its tools are free with no registration fee or usage cap. The other four private-sector IRPs (Cygnet, Clear, EY, IRIS, Masters India) are also CBIC-notified and interoperable.

All IRPs generate the same IRN — because the hash is deterministic, the output is identical regardless of which portal processes the submission. Choose the one whose interface suits your workflow.

Tool 1: NIC e-Invoice Web Portal (einvoice1.gst.gov.in)

A browser-based form for single-invoice entry. No download, no API credentials. Log in with your GST portal credentials, fill the tabbed sections (transaction details, seller, buyer, item lines, value summary), and submit. The portal validates in real time and returns the signed JSON with IRN and QR code.

• Best for: Businesses raising fewer than 30 invoices per month
• Output: Downloadable signed JSON + a system-generated PDF with IRN and QR code already embedded

Tool 2: GSTN Offline Excel Utility (Bulk)

A prescribed Excel template for batch processing, available on the NIC portal under Bulk Generation. Fill one row per invoice across the template's structured sheets, run the offline validator to catch errors before upload, then submit the batch to the portal. The portal returns IRNs for successful records and an error log for rejections.

• Best for: Businesses raising 30–200 invoices per month
• Output: Results Excel file with the IRN column populated for each accepted invoice

Tool 3: NIC e-Invoice Mobile App

The official NIC app (available on Google Play Store; search "e-Invoice" by NIC) supports single-invoice generation, IRN search by invoice number, IRN cancellation within the 24-hour window, and QR code scanning for verification. It uses the same GST credentials as the web portal.

• Best for: Field sales teams, on-site invoice generation, and delivery verification
• Limitation: Not suitable for batch generation — one invoice at a time only

Tool 4: GSP Free-Tier APIs

Several authorised GST Suvidha Providers (GSPs) — including Masters India, ClearTax, and Cygnet — offer free-tier API access for low monthly volumes (typically 50–100 IRNs per month on free plans). If your accounting software — Zoho Books, Tally Prime, or similar — already has a GSP integration configured, you may already be generating IRNs through this route without realising it. Check your software's e-invoice settings tab before setting up a parallel manual process.

Step-by-Step: Your First IRN on the NIC Web Portal

This assumes your GSTIN is already registered on einvoice1.gst.gov.in. If not, the one-time registration takes under five minutes: visit the portal, click Registration, and authenticate with your GST login credentials.

1. Log in at einvoice1.gst.gov.in using your GSTIN and password.
2. Navigate to Generate New → Invoice from the left panel.
3. Transaction Details tab: Select Supply Type (B2B, EXPWP, or EXPWOP), Document Type (INV for invoice, CRN for credit note, DBN for debit note), Invoice Number, and Invoice Date.
4. Seller Details tab: Your GSTIN, trade name, and registered address auto-populate. Confirm the pin code — it determines state code, which drives IGST vs CGST/SGST calculation.
5. Buyer Details tab: Enter the buyer's GSTIN. The portal auto-fetches the registered trade name and address from the GSTN database. Verify manually — this is the single most common error point. A single transposed digit sends the ITC to the wrong taxpayer.
6. Item Details tab: For each line item, enter the HSN/SAC code, item description, unit (using UQC codes — NOS, KGS, MTR, etc.), quantity, unit price, and any discount. Select the applicable GST rate. The portal computes taxable value and IGST/CGST/SGST automatically.
7. Value Details tab: Review computed totals. Correct any rounding difference here — the portal enforces that item-level subtotals must reconcile with the header value.
8. Click Save and Submit. Validation completes in seconds; the IRN appears in the confirmation screen.
9. Download the signed JSON (retain for your records) and the system-generated PDF with the QR code. You may use this PDF or integrate the IRN and QR code into your own branded invoice template.
10. Send the invoice only after downloading the IRN. The dispatch must happen after, not before, IRN generation.

Important timing rule: The invoice date you enter must match or precede the IRN generation date. You cannot backdate e-invoices — the Acknowledge Date stamped on the signed JSON reflects the actual generation time and is immutable. This means you cannot generate IRNs in advance for future-dated invoices either, without the invoice date matching.

Step-by-Step: Bulk IRN Generation with the GSTN Offline Utility

1. Download the current bulk upload Excel template from einvoice1.gst.gov.in → Bulk Generation → Download Template. Always download fresh — schema fields are updated periodically.
2. Populate the template sheets: Sheet 1 covers transaction and header data; Sheet 2 covers seller and buyer details; Sheet 3 covers item line data; Sheet 4 covers value summary. Each invoice has one header row and as many item rows as there are line items, linked by a batch reference column.
3. Open the offline validation utility (separate download from the same page) and load your Excel. Run Validate. Fix every flagged error — wrong GSTIN format, invalid HSN, missing mandatory fields, UQC mismatch — before proceeding. A batch with structural errors may be rejected wholesale.
4. The utility converts the validated Excel to a JSON batch file automatically. Save this JSON.
5. Log in to einvoice1.gst.gov.in → Bulk Generation → Upload JSON. Select your batch file and submit.
6. The portal processes the batch and returns a results file with the IRN column filled for accepted invoices and error descriptions for rejections.
7. For rejected rows, fix the specific error, create a new batch containing only those records, and re-upload. You cannot partially resubmit; each upload is a fresh batch.
8. Embed the IRN and QR code (both in the results file) onto your invoice PDFs before dispatching to buyers.

Worked Example: A Pune Manufacturer Generates Their First E-Invoice

Background: M/s Lakshmi Engineering Works, GSTIN 27XXXXX (Pune, Maharashtra), manufactures industrial valves. FY 2024-25 turnover: ₹6.40 crore. E-invoice liability triggered from April 1, 2025 — and continues through FY 2026-27.

Invoice details:

The accounts person logs into einvoice1.gst.gov.in at 10:28 AM on April 5. They select Supply Type B2B, Document Type INV, enter the invoice number and date. In the buyer tab, they paste the Delhi GSTIN — the portal auto-fills "M/s Raj Industrials" with the registered address. In the item tab: HSN 8481, description "Industrial Ball Valve", UQC NOS, quantity 50, unit price ₹4,000, IGST 18%. The portal computes ₹2,00,000 taxable value, ₹36,000 IGST, total ₹2,36,000.

On submission at 10:31 AM:

• IRN generated: 64-character alphanumeric hash (unique to this GSTIN + FY 2026-27 + INV + LEW/2026-27/001)
• Acknowledge Date: 05/04/2026 10:31 AM (immutable)
• Signed JSON + QR code PDF: downloaded and archived

The invoice, with QR code embedded, is emailed to Raj Industrials at 10:35 AM.

What Raj Industrials sees: By May 14, 2026 (GSTR-2B generation date for April), Invoice LEW/2026-27/001 appears in Raj Industrials' GSTR-2B with ₹36,000 ITC available. No manual addition, no reconciliation query raised, no call to the supplier.

If no IRN had been generated: Raj Industrials would not see the invoice in GSTR-2B. Their accounts team would query the invoice in their reconciliation cycle, flag Lakshmi Engineering as a non-compliant vendor, and potentially delay the ₹2,36,000 payment pending resolution. The ₹36,000 ITC — which Raj Industrials was counting on against their April tax liability — is unavailable, increasing their cash outflow for that month.

Common Mistakes That Create Real Problems

1. Dispatching the invoice before generating the IRN Rule 46 of the CGST Rules is unambiguous: a tax invoice must carry the IRN before it is issued to the recipient. Dispatching first and generating the IRN later creates an Acknowledge Date later than the supply date — a documentary inconsistency that surfaces in audit. Build a workflow gate: no dispatch without IRN confirmation.

2. Attempting to cancel after the 24-hour window IRN cancellation is permitted only within 24 hours of generation, and only if the e-waybill linked to the IRN has not already been generated. After 24 hours, there is no edit or cancel function. Your only remedy is:

• A credit note against the original invoice (which itself generates a new IRN)
• A fresh correct invoice (another new IRN)

This doubles document count and requires careful GSTR-1 reconciliation. Catching errors within the same working day is operationally critical.

3. Entering the wrong buyer GSTIN If the GSTIN is syntactically invalid, the IRP rejects the submission immediately. If it belongs to a different registered entity (a common transposition error — e.g., swapping two digits in a 15-character GSTIN), the submission succeeds and the ITC flows to the wrong taxpayer. Your intended buyer gets no automatic credit. Prevention: validate every new buyer GSTIN on the GSTN search portal before creating the party master, and re-validate annually — GSTINs get cancelled or transferred.

4. Omitting the QR code from the printed invoice Rule 46 mandates the machine-readable QR code returned by the IRP on every e-invoice. Printing the IRN as a text string without the QR code is non-compliant. Resizing the QR code image to the point where it fails to scan is also non-compliant. Use the QR code image from the IRP output, and test it with a standard QR scanner before finalising your invoice template.

5. Using last year's invoice number series in April The IRN hash incorporates the financial year. If your accounting software or manual process fails to reset the invoice series at the start of FY 2026-27, you may raise invoices numbered in last year's sequence. The IRN will generate successfully — but the financial year in the hash will reflect the current year, creating a mismatch between your invoice records and the IRP-generated hash that can be difficult to explain in a GST audit.

6. Treating the IRP PDF as your invoice The IRP-generated PDF is a convenience output, not a legal requirement. You are permitted — and usually expected — to use your own branded invoice template. What is mandatory is that your template carries all fields required under Rule 46, including the IRN and the QR code returned by the IRP. Most businesses add an IRN field and QR code block to their existing template.

When Free Tools Are No Longer Enough

The NIC portal and offline utility are entirely compliant tools. Graduating to API integration is an operations decision, not a compliance one.

At 300 invoices per month, manual Excel preparation typically consumes 4–6 staff hours per batch cycle. Direct API integration through Tally Prime, Zoho Books, or a dedicated GSP costs approximately ₹6,000–₹20,000 per year at this volume tier — recoverable within two months from time saved alone.

Consider moving to API integration earlier if any of the following apply:

• You have multiple GSTINs generating invoices concurrently
• Your buyers are large enterprises with automated GSTR-2B reconciliation teams who will flag every missing IRN
• You have high amendment frequency — frequent credit notes and debit notes multiply manual work non-linearly
• Your logistics process requires real-time IRN at point of dispatch (courier or transporter insists on seeing the QR code before pickup)

Regardless of the tool you use, build one non-negotiable daily discipline: reconcile your sales register against generated IRNs at end of day. A missing IRN found the same day can be generated and the invoice re-dispatched. One discovered after the GSTR-1 due date forces a credit note and reinvoicing cycle — two extra documents, two extra IRNs, and a conversation with your buyer you would rather not have.

Key Takeaways

• The ₹5 crore aggregate turnover threshold (any financial year from FY 2017-18 onwards) makes e-invoicing mandatory for all B2B invoices, exports, and credit/debit notes in FY 2026-27 — there is no minimum invoice value exemption.
• einvoice1.gst.gov.in (NIC portal) is free, requires no software, and handles single-invoice IRN generation via browser for up to ~30 invoices per month; the GSTN offline Excel utility scales this to 30–200 per month.
• IRN generation must precede dispatch — the IRP's Acknowledge Date is immutable and forms part of the legal invoice record; backdating is not possible.
• Cancellation is only permitted within 24 hours of generation and only if no linked e-waybill exists; errors discovered later require a credit note and fresh invoice.
• Wrong buyer GSTIN is the leading cause of both IRP rejection and downstream ITC loss — validate every new party master before raising the first invoice, and revalidate annually.
• The QR code on the printed invoice is a Rule 46 requirement, not optional; a text IRN without a scannable QR code is non-compliant.
• Evaluate the move from free tools to API or software-plugin integration at the 200–500 invoice per month threshold — the annual cost of ₹6,000–₹20,000 is typically recovered within two months through reduced processing time and error elimination.