GST Invoice vs. Bill of Supply vs. Non-GST Invoice: The Complete 2026 Guide

A practical, plain-English guide for Indian business owners, freelancers, and accountants.

You make a sale. Now comes the part that quietly decides whether your books stay clean or trigger a tax notice: which document do you issue? Pick a tax invoice when you should have used a bill of supply, and you may be accused of wrongly collecting GST. Skip a tax invoice when one was due, and your buyer loses their input tax credit. The wrong choice can cost you penalties and your customer their refund.

The confusion is understandable. A GST invoice, a bill of supply, and a non-GST invoice can look almost identical on paper. The real difference lies in the tax. This guide breaks down all three documents in simple terms, explains the bill of supply vs tax invoice question that trips up most sellers, and answers the big one head-on: when should I issue a bill of supply instead of a tax invoice?

The Three Documents at a Glance

Every sale in India produces one of three billing documents. Each one signals something different about tax. Before we dive deep, here is the quick mental model.

What Is a GST Tax Invoice?

A GST tax invoice is the standard billing document issued by a regular GST-registered dealer whenever they make a taxable supply of goods or services. It is governed by Section 31 of the CGST Act, 2017, while Rule 46 of the CGST Rules prescribes the exact details it must carry. The invoice does three jobs at once: it records the tax you owe the government, it lets your buyer claim input tax credit, and it allows the system to match your sales return (GSTR-1) against your buyer's auto-populated statement (GSTR-2B).

Because the tax invoice is the foundation of the input tax credit chain, accuracy matters. A valid tax invoice must show a unique consecutive invoice number (no more than 16 characters) for the financial year, the date, your name, address, and GSTIN, the customer's details and GSTIN where they are registered, the place of supply, the HSN or SAC code, a clear description of goods or services, the taxable value, and the tax split shown separately as CGST and SGST for intra-state sales or IGST for inter-state sales. When the recipient is unregistered and the invoice value crosses ₹50,000, the buyer's name, address, and delivery state become mandatory too.

When Must a Tax Invoice Be Issued?

Timing is part of compliance. For goods, the invoice must be raised on or before the goods are removed or delivered to the buyer. For services, it must be issued within 30 days of completing the service. Late or back-dated invoices are a leading cause of GSTR-1 and GSTR-2B mismatches, which then delay or deny your customer's credit. The simplest rule is to make the invoice part of the moment of supply, not an afterthought you handle at month-end.

A Word on E-Invoicing

If your aggregate annual turnover crosses the notified threshold, your business-to-business tax invoices must be reported to the Invoice Registration Portal to receive an Invoice Reference Number (IRN) and a QR code before they are valid. The threshold has tightened steadily and now reaches businesses with turnover above ₹5 crore. Importantly, e-invoicing applies only to tax invoices on taxable supplies. A bill of supply never needs an IRN. You can confirm the current threshold and rules on the official GST portal (gst.gov.in) or the CBIC GST website.

What Is a Bill of Supply?

A bill of supply is a billing document issued by a GST-registered person who is not allowed to charge GST on a particular transaction. It looks much like a tax invoice in layout, but it carries no CGST, SGST, or IGST because no tax is being collected from the buyer. Its purpose is simple yet vital: it records the sale, proves the transaction happened, and clearly communicates that the supply carried no GST. Because no tax was charged, a bill of supply does not let the buyer claim any input tax credit.

The bill of supply still needs proper details to be valid. It carries the supplier's name, address, and GSTIN, a unique consecutive number for the financial year, the date, the recipient's details and GSTIN where applicable, an HSN or SAC code, and a description and value of the goods or services. The one thing it never shows is a tax amount.

What Is a Non-GST Invoice?

This is where people often blur lines, so let us be precise. A non-GST invoice covers situations where GST simply does not apply to the transaction in the first place. The two common cases are supplies that fall outside the GST net altogether, and sales by businesses that are not registered under GST.

Certain goods sit outside GST by law. These include petrol, diesel, natural gas, aviation turbine fuel, and alcohol meant for human consumption, which continue to attract older taxes such as VAT or excise. A document covering these items is effectively a non-GST invoice, because GST never enters the calculation. Separately, a business whose turnover is below the registration threshold is not required to register at all. Such a seller raises an ordinary invoice with no GST, no GSTIN, and no tax line. This directly answers a question many small sellers ask: can I issue an invoice without GST? Yes, you can, as long as you are genuinely outside the GST system, either because you are unregistered or because the supply is a non-GST supply.

GST Invoice vs. Bill of Supply vs. Non-GST Invoice: Side-by-Side

Here is the full comparison in one table. Bookmark this; it answers most day-to-day billing doubts.

What Is the Difference Between a Tax Invoice and a Bill of Supply?

If you remember only one thing about the bill of supply vs tax invoice debate, make it this: a tax invoice charges GST and passes on input tax credit, while a bill of supply does neither. A tax invoice is the engine of the credit chain. When your buyer holds a valid tax invoice, they can reduce their own GST liability by the tax shown on it. A bill of supply, by contrast, breaks that chain because there is no tax to pass along. Buy from a composition dealer and you walk away with a record of your purchase, but no credit.

The second difference is the people who issue them. A tax invoice comes from a regular registered dealer charging GST. A bill of supply comes from a narrower set: composition dealers, sellers of exempt or nil-rated goods, and exporters. The third difference is content. A tax invoice splits out CGST, SGST, or IGST line by line, whereas a bill of supply shows the value of the supply with no tax line at all. Same shape, very different meaning.

When Should I Issue a Bill of Supply Instead of a Tax Invoice?

This is the heart of the matter, and the rule is refreshingly clear. You issue a bill of supply instead of a tax invoice whenever you are registered under GST but are not permitted to charge GST on that particular sale. That happens in three well-defined situations.

The first is when you have opted for the Composition Scheme. Composition dealers pay a small fixed percentage of turnover as tax out of their own pocket and are barred from collecting GST from customers, so every sale they make goes out on a bill of supply rather than a tax invoice. The second is when you supply goods or services that are exempt or nil-rated, such as unprocessed agricultural produce or specified handloom items. Even a regular registered dealer must drop to a bill of supply for those particular goods, because there is no tax to charge. The third is export. Because exports are treated as zero-rated supplies, an exporter selling under a bond or Letter of Undertaking without paying IGST issues a bill of supply, adding the prescribed export declaration on the document.

Below is the decision logic in a single glance.

Who Needs to Issue a Bill of Supply?

The set of businesses required to issue a bill of supply is small and specific. Composition Scheme dealers head the list, since they cannot legally collect tax. Registered dealers who supply exempt or nil-rated goods or services come next, because no GST applies to those items. Exporters round out the group, as their supplies are zero-rated. Notably, an unregistered person is not required to issue a bill of supply at all; they may issue an ordinary invoice voluntarily, since GST law does not apply to them in the first place.

One practical point worth highlighting: a single registered business can issue both documents. If you are a regular dealer who sells taxable goods alongside some exempt goods, you raise a tax invoice for the taxable items and a bill of supply for the exempt ones. To keep this clean, GST law allows an "invoice-cum-bill of supply" — a single combined document — when you supply both taxable and exempt items to the same unregistered customer.

What Invoice Does a Composition Dealer Use?

The composition dealer rule

A composition dealer uses a bill of supply for every sale — never a tax invoice. The Composition Scheme is built for smaller businesses, typically those with annual turnover up to ₹1.5 crore (₹75 lakh in the north-eastern states and Uttarakhand). In exchange for paying a low flat rate on turnover, these dealers give up two privileges: they cannot collect GST from customers, and they cannot claim input tax credit on their own purchases. Since they have no tax to pass on, a tax invoice would be meaningless and, in fact, illegal for them.

The law also requires the composition dealer to print a specific declaration on the document — words to the effect that they are a "composition taxable person, not eligible to collect tax on supplies." That line tells the buyer plainly that no GST has been charged and none can be claimed back. If you are weighing whether the scheme suits you, the eligibility details are laid out on the CBIC GST portal, and you can read a deeper explanation of the scheme on ClearTax's composition scheme guide.

Special Cases You Should Know

A few real-world scenarios sit slightly outside the neat three-way split, and knowing them saves headaches. When a sale is small in value, the law eases the paperwork: if an individual supply is below ₹200 and the buyer is unregistered and does not ask for a document, you may skip the separate bill and instead issue one consolidated bill of supply at the close of each day. For exporters, the bill of supply must carry one of two declarations depending on whether IGST was paid or the export was made under bond or Letter of Undertaking. And for mixed baskets — taxable plus exempt items in the same transaction — the invoice-cum-bill of supply keeps everything on one tidy document.

Why Getting the Document Right Actually Matters

This is not just bookkeeping pedantry. Issuing a tax invoice when you should have issued a bill of supply can be read as wrongly collecting tax, which invites penalties. Failing to issue a bill of supply when required is itself a compliance lapse. A non-compliant tax invoice — one missing even a single mandatory Rule 46 field — can be treated as invalid, blocking your buyer's input tax credit and exposing you to penalties that can run into thousands of rupees per invoice. In short, the right document protects your money, your buyer's credit, and your standing in any future GST audit.

Conclusion

The difference between a GST invoice, a bill of supply, and a non-GST invoice comes down to one quiet question asked at every sale: is GST being charged, and am I allowed to charge it? A regular registered dealer making a taxable sale issues a tax invoice and passes on input tax credit. A composition dealer, an exempt-goods seller, or an exporter issues a bill of supply with no tax shown. And when GST does not apply at all — non-GST goods or an unregistered seller — a plain non-GST invoice does the job. Master that single distinction and you stay compliant, keep your buyers' credit intact, and sail through audits. When you are ready to put it into practice, the right tool turns the rules into a two-minute task.

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