Search 'GST invoice format' and you will find thousands of templates — most of them do not explain when that format is actually needed.

Under Indian GST, a 'tax invoice' is a very specific thing with mandatory fields; a 'proforma' or 'commercial invoice' is not a GST document at all.

This guide explains what a real GST invoice is, then positions other invoice types around it so you never again send the wrong document for the job.

Stop fighting with invoice templates.

Generate a legally compliant, highly professional invoice in under 60 seconds.
No signup required to start. No credit card. Just type, send, done.

Show me how

The GST invoice: your official tax and ITC document

A GST invoice (also called a tax invoice) is the official document a registered supplier issues for taxable supplies — it's what lets the buyer claim input tax credit.
It must include supplier and recipient details, GSTINs, HSN/SAC codes, place of supply, GST rate, tax breakup, and other fields mandated under GST rules.
For B2B, your buyer's CA and GST system care about this document more than any email or WhatsApp message.
If you are GST-registered and issue anything else in place of a proper GST invoice for taxable supplies, your buyer's ITC and your compliance both stand on thin ice.

Proforma invoice: quotation dressed like an invoice

A proforma invoice is essentially a detailed quote or estimate — it looks like an invoice but is not used for GST or ITC.
You send it before finalising the order to show expected quantity, price, tax rate, and terms, especially for custom work or imports/exports.
Because it is not a tax invoice, it should be clearly labeled 'Proforma Invoice' and should not be uploaded as a supply in GST returns.
Once the client confirms, you convert the proforma into a real tax invoice with an official invoice number in your series.

Tax invoice vs commercial invoice (especially in exports)

In domestic Indian GST, 'tax invoice' and 'GST invoice' usually mean the same thing — the formal invoice charging GST.
In international trade, a 'commercial invoice' often travels with goods across borders and is used by customs and banks; it may or may not be the same as your GST tax invoice.
For exports, your GST invoice must still follow Indian rules (including GST/LUT language), while the commercial invoice may have extra fields like Incoterms, port details, and foreign currency values.
The safest pattern is: one GST-compliant tax invoice for the Indian side, and, where needed, a commercial invoice that satisfies shipping and foreign buyer requirements — often with cross-border eferences.

Types of invoices you actually need in one MSME

GST tax invoice: for all taxable B2B/B2C supplies once you are registered.
Bill of supply: for exempt goods/services or composition scheme dealers who cannot charge GST.
Proforma invoice: for serious quotes where the client or bank wants a near-final document before committing.
Commercial/export invoice: for cross-border shipments where customs and foreign buyers need more than your domestic GST layout.

The GST invoice: your official tax and ITC document

A GST invoice (also called a tax invoice) is the official document a registered supplier issues for taxable supplies — it's what lets the buyer claim input tax credit.

It must include supplier and recipient details, GSTINs, HSN/SAC codes, place of supply, GST rate, tax breakup, and other fields mandated under GST rules.

For B2B, your buyer's CA and GST system care about this document more than any email or WhatsApp message.

If you are GST-registered and issue anything else in place of a proper GST invoice for taxable supplies, your buyer's ITC and your compliance both stand on thin ice.

Proforma invoice: quotation dressed like an invoice

A proforma invoice is essentially a detailed quote or estimate — it looks like an invoice but is not used for GST or ITC.

You send it before finalising the order to show expected quantity, price, tax rate, and terms, especially for custom work or imports/exports.

Because it is not a tax invoice, it should be clearly labeled 'Proforma Invoice' and should not be uploaded as a supply in GST returns.

Once the client confirms, you convert the proforma into a real tax invoice with an official invoice number in your series.

Tax invoice vs commercial invoice (especially in exports)

In domestic Indian GST, 'tax invoice' and 'GST invoice' usually mean the same thing — the formal invoice charging GST.

In international trade, a 'commercial invoice' often travels with goods across borders and is used by customs and banks; it may or may not be the same as your GST tax invoice.

For exports, your GST invoice must still follow Indian rules (including GST/LUT language), while the commercial invoice may have extra fields like Incoterms, port details, and foreign currency values.

The safest pattern is: one GST-compliant tax invoice for the Indian side, and, where needed, a commercial invoice that satisfies shipping and foreign buyer requirements — often with cross-border eferences.

Types of invoices you actually need in one MSME

GST tax invoice: for all taxable B2B/B2C supplies once you are registered.

Bill of supply: for exempt goods/services or composition scheme dealers who cannot charge GST.

Proforma invoice: for serious quotes where the client or bank wants a near-final document before committing.

Commercial/export invoice: for cross-border shipments where customs and foreign buyers need more than your domestic GST layout.

What is a GST invoice in India? And how it differs from proforma, tax, and commercial invoices

Stop fighting with invoice templates.

The GST invoice: your official tax and ITC document

Proforma invoice: quotation dressed like an invoice

Tax invoice vs commercial invoice (especially in exports)

Types of invoices you actually need in one MSME

Keep reading

GST tax invoice rules in India: every mandatory field explained

HSN and SAC codes explained — a practical guide for Indian businesses

What is a GST invoice in India? And how it differs from proforma, tax, and commercial invoices

Stop fighting with invoice templates.

The GST invoice: your official tax and ITC document

Proforma invoice: quotation dressed like an invoice

Tax invoice vs commercial invoice (especially in exports)

Types of invoices you actually need in one MSME

Keep reading

GST tax invoice rules in India: every mandatory field explained

HSN and SAC codes explained — a practical guide for Indian businesses