GST Invoice Generator

How this is worked out

India has the most prescriptive invoice of the five markets on this site. Rule 46 of the CGST Rules lists the particulars, and two of them exist nowhere else here: an HSN code for goods or a SAC code for services against every line, and a place of supply naming the state.

The place of supply decides the tax heads, and the tool derives it rather than asking. The first two digits of every GSTIN are the registrant's state. Compare your own GSTIN's state code with the place of supply: the same state means the rate splits equally into CGST and SGST; a different state means the whole rate is IGST. Deriving it from the two things already on the form is the only way the invoice cannot contradict itself.

same state → CGST 9% + SGST 9%  ·  different state → IGST 18%

The customer pays the same total either way. That is exactly why this is got wrong so often — the money adds up, so nothing looks wrong, and the error surfaces months later in the recipient's input-credit claim rather than at the point of sale.

The serial number is law here, not convention. Rule 46(b) requires a consecutive number, unique within the financial year, of at most sixteen characters, using only letters, numbers, hyphen and slash. A series that restarts mid-year or runs to seventeen characters is defective on its face. In the US, UK, Canada and Australia this is good practice; in India it is a requirement, and the checklist treats it as one.

And if you are not registered for GST, what you may issue is a bill of supply — a different document that charges no tax and shows no tax columns. Leave the GSTIN blank and the title changes accordingly. The same applies if you supply only exempt goods or are under the composition scheme. Issuing a tax invoice when you are not entitled to collect GST is a separate problem from issuing a defective one, and a worse one.

A worked example

Why the same total can still be the wrong invoice

On ₹1,56,000 at 18%, the tax is ₹28,080 whichever way it is reported. Within one state that is CGST ₹14,040 plus SGST ₹14,040; across state lines it is IGST ₹28,080. Your customer pays ₹1,84,080 either way and nothing on the invoice looks wrong.

What breaks is the credit. Your customer claims input tax credit against the heads you reported under, and a mismatch between your GSTR-1 and what their supply actually was blocks or reverses that claim. They find out at reconciliation, which is months later, and the person who has to fix it is you — by issuing a credit note and a corrected invoice, after the return has already been filed.

The rule is that the place of supply governs, not the billing address and not where the work was done. For most services the place of supply is the location of the registered recipient. Getting this right on the invoice is cheap; getting it wrong is a reconciliation and a revised return.

HSN and SAC — the classification no other market asks for

Rule 46(d) requires a classification code against each line: HSN for goods, SAC for services. Six digits where your aggregate turnover exceeds ₹5 crore, four digits at or below that for business-to-business supplies, and generally optional at four digits for business-to-consumer supplies.

The code is yours to identify from what you are actually supplying, and it is not a formality — the rate follows the classification. 998314 covers information technology design and development services, which is why it is the sample on this page. A wrong code that carries a different rate is a wrong rate, and the liability for that is the supplier's.

Neither the US, UK, Canada nor Australia asks for anything comparable on an invoice, which is why people building their first Indian invoice from a foreign template leave the column off entirely. The checklist here marks it missing rather than letting it pass.

Time limits, the ₹200 floor and the ₹50,000 rule

For goods, the invoice must be issued on or before removal — section 31(1)(a). For services, within 30 days of the supply, extended to 45 days for banks, insurers and non-banking financial companies — section 31(2) with Rule 47. These are not billing conventions; they are the statutory deadlines, and an invoice dated outside them is late in a way that matters at assessment.

At the small end, section 31(3)(b) means no tax invoice need be issued at all for a supply under ₹200 to an unregistered recipient who does not ask for one. Most people issuing a consolidated daily invoice for small retail supplies are relying on this.

At the other end, Rule 46(f): where the recipient is unregistered and the taxable value reaches ₹50,000, the invoice must carry their name, address, delivery address, the name of the state and the state code. Below that, only on request. The checklist here tracks the total and says which tier you are in as you type.

E-invoicing, the IRN, and what this tool cannot do

E-invoicing through the Invoice Registration Portal is mandatory under Rule 48(4) above ₹5 crore of aggregate annual turnover — and the threshold is cumulative. Crossing it in any single year since FY 2017-18 keeps you inside it permanently, even if turnover has since fallen well below. A great many small businesses do not realise they are still in scope.

Above ₹10 crore, an invoice must be reported to the portal within 30 days of its date, and the portal rejects late uploads outright with no grace period. Reporting is not optional paperwork after the fact; an unreported invoice is not a valid tax invoice for a taxpayer in scope.

This tool produces a compliant document. It does not register one. A registered e-invoice carries an Invoice Reference Number and a QR code that only the portal can generate, and no browser-based generator can produce either. If you are in scope for e-invoicing, use this to get the particulars right and your accounting software or the portal to register it.

Assumptions and sources

India — particulars required on a tax invoice

Rule 46 of the CGST Rules 2017, read with section 31 of the CGST Act: consecutive serial number unique for the financial year and no more than sixteen characters, supplier and recipient identity and GSTIN, HSN or SAC code, quantity and unit, taxable value, rate and amount per tax head, place of supply with the state name, delivery address where it differs, reverse-charge declaration and signature. TaxGuru. https://taxguru.in/goods-and-service-tax/tax-invoice-requirements-section-31-cgst-act-gst-rule-46.html checked 2026-09

India — time limits and the small-value exemption

Section 31(1)(a): for goods, on or before removal. Section 31(2) with Rule 47: for services, within 30 days of supply, extended to 45 days for banks, insurers and NBFCs. Section 31(3)(b): no tax invoice need be issued for a supply under ₹200 to an unregistered recipient who does not ask for one. A bill of supply replaces the tax invoice for exempt supplies and composition dealers. IncorpX. https://www.incorpx.io/blog/gst-invoice-rules-format-mandatory-fields checked 2026-09

India — HSN digits and the ₹50,000 recipient rule

Six-digit HSN or SAC above ₹5 crore of aggregate turnover, four digits at or below it for B2B supplies. Rule 46(f): an unregistered recipient must be named, with address, delivery address, state and state code, once the taxable value reaches ₹50,000. GimBooks. https://www.gimbooks.com/blog/gst-invoice-mandatory-fields-rule-46-checklist/ checked 2026-09

India — e-invoicing threshold

Rule 48(4): mandatory above ₹5 crore of aggregate annual turnover, assessed cumulatively from FY 2017-18 onwards. Above ₹10 crore, invoices must be reported to the Invoice Registration Portal within 30 days of the invoice date. https://www.digitaldreamsinfotech.com/post/gst-e-invoicing-rules-2026-turnover-limit-sme-guide checked 2026-09

GST slabs and the CGST/SGST/IGST split

The slab table, the September 2025 reform and the split rule are carried in assets/js/tax/in-2026-27.js with their own source lines, so the rates this form offers and the rates the GST calculator quotes cannot disagree.

GST state codes

The two-digit state codes at the front of every GSTIN, used here to derive the supply type. Held in assets/js/tax/in-2026-27.js; codes 25 and 28 are retained as historic and are never offered for a new invoice. checked 2026-09

Bill of supply

Required instead of a tax invoice where the supplier is unregistered, supplies only exempt goods or services, or is under the composition scheme — no tax charged and no tax columns shown. checked 2026-09

Not covered

State and local US sales tax rates and taxability, Quebec's mandatory billing rules and QST invoicing requirements, EU cross-border VAT and OSS, e-invoicing mandates, Making Tax Digital, construction industry schemes, and late-payment interest legislation.